asphalt-rubber binder laboratory performance · however, observations and tests made in the fi.eln...
TRANSCRIPT
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li
TTI-2-9-83-347-1F
TEXAS TRANSPORTATION INSTITUTE
STATE DEPARTMENT OF HIGHWAYS AND PUBLIC TRANSPORTATION
COOPERATIVE RESEARCH
ASPHALT-RUBBER BINDER LABORATORY PERFORMANCE
RESEARCH REPORT 347 -IF STUDY 2-9-83-347 ASPHALT-RUBBER BINDERS
II I!
in cooperation with the Department of Transportation Federal Highway Administration
Technical keport Documentation Page
1. Report No. 2. Government Accession No. 3. Recipient's Catalog No.
FHWA/TX-85/ 71 +347-W
4. Title and Subtitle 5. Report Dote
Asphalt-Rubber Binder Laboratory Performance ~~t, 1985 ·-----'1 6. Performing Orgoni zation Code
~~~~~~~~~~~~~~~~~~~~~~~~~-~~-~ 8. Performing Organization Report No. 7
. Su~~tf Shuler, Cindy Adams, and Mark Lamborn Research Report 34 7 -lF
9. Performing Organization Nome and Address
Texas Transportation Institute The Texas A&M University System College Station, Texas 77843
10. Work Unit No. (TRAIS)
11. Contract or Grant No.
Study 2-9-83-347 13. Type of Report and Period Covered
12. Sponsoring Agency Nome and Address -----------~~~~---1 Inte • _ September 1983 r:un March 1985 Texas State Department of Highways and Public
Transportation: Transportation Planning Division Austin, Texas 78763 14. Sponsoring Agency Code
15. Supplementary Notes
Research perfonned in cooperatiOn. with OOT, FHWA. Research Title: Econanic Asphalt Treated Bases
16. Abstract
Three experimental test roads containing asphalt-rubber interlayers were constructed. Test pavements were designed as statistical experiments such that future perfonnance analysis could be obtained. Precondition surveys were conducted prior to rehabilitation to provide documentation for future condition surveys.
Samples of asphalt-rubber were obtained during field rrdxing of asphalt and rubber for laboratory characterization. Samples of asphalt and rubber were obtained for mixing in the laboratory. A comparison was made between laboratory test results of field and laboratory prepared asphalt-rubber.
'Three new laboratory tests were used to evaluate asphalt-rubber engineering properties. These included force ductility, double ball softening point, and torque fork viscosity.
Results of these laboratory tests indicate engineering properties of field prepared asphalt-rubber can be duplicated by laboratory prepared rrdxtures. This means future rrdxtures of asphalt-rubber can be designed in the laboratory prior to construction. .
Procedures are described VJhich would allow prediction of rubber content fran rotational viscosity data. Prediction of rubber content could be possible in the field by highway department personnel responsible for quality assurance.
17. Key Words
Asphalt-rubber, stress absorbing membrane interlayers, seal coats factorial design, Latin square design
18. Distribution Statement
No restrictions. This document is available to the public through the National Teclmical Infonnation Service, 5285 Port Royal Road, Springfield, Virginia 22161
19. Security Classif. (of this report) 20. Security Clossif. (of this page) 21. No. of Pages 22. Price
Unclassified Unclassified 282
Form DOT F 1700.7 (8-72) Reproduction of completed page authorized
Asphalt-Rubber Binder Laboratory Performance
by
Scott Shuler
Cindy Adams
and
Mark Lamborn
Research Study Number 2-9-83-347
Report No. 347-lF
Sponsored by the
State Department of
Highways and Public Transportation
. in cooperation
with the
United States Department of Transportation
Federal Highway Administration
Texas Transportation Institute
Texas A&M University
College Station, Texas 77843
August, 1985
ORJ :OCTIVES
This project was intended to design and supervise construction of
three expernnental test roads containing asphalt-rubber as interlayer
binders. Control sections were included. Asphalt-rubber was ohtained
from each test road as prepared in the field. Asphalt-rubber was also
fabricated in the laboratory. Properties of asphalt-rubber prepared
under both conditions were determined by force ductility, double ball
softening point, and rotational viscosity.
Future correlation of laboratory properties and field performance
should be possible due to extensive precondition surveys conducted at
each test road.
ii
DISClAIMER
'Ibe contents of this report reflect' the views of the authors who are
responsible for the facts and the accuracy of the data presented herein.
The contents do not necessarily reflect the official views or policies of
the Federal Highway Administration. This report does not constitute a
standard, specification or requlation.
iii
ABSTRACT
Three expernnental test roads containing asphalt-rubber interlayers
were constructed. Test pavements were oesigned as statistical
experiments such that future performance analysis could he obtained.
Precondition surveys were conducted prior to rehabilitation to provide
documentation for future condition surveys.
Samples of asphalt-rubber were obtained during field rnixinq of
asphalt and rubber for laboratory characterization. Samples of asphalt
and rubber were obtained for mixing in the laboratory. A COIT{)arison was
made between laboratory test results of field and laboratory prepared
asphalt-rubber.
Three new laboratory tests were used to evaluate asphalt-rubber
engineering properties. These included force ductility, double ball
softening point, and torque fork viscosity.
Results of these laboratory tests indicate enqineering properties of
field prepared asphalt-rubber can be duplicated by laboratory prepared
mixtures. This means future mixtures of asphalt-rubber can be designed
in the laboratory prior to construction.
Procedures are described which would allow prediction of rubber
content from rotational viscosity data. Prediction of rubber content
could be possible in the field by highway department personnel
responsible for quality assurance.
Keywords: asphalt-rubber, stress absorbing membrane
interlayers, seal coats, force ductility, Latin Square design, factorial
de$ign.
iv
ACKN0~1LEDGEMENTS
TTI wishes to thank the Texas State Department of Hiqhways and
Public Transportation, Research Area II Ccmnittee, Districts 24, 17, and
21 without whose cooperation and sponsorship, this work would not have
been poSsible, and ~o Donald O'Connor, File D-9, for valuable discussions
and advice provided during the ca1rse of this work.
'!hanks are also due Crafco, Inc. and Arizona Refining Coopany for
voluntary cooperation and helpful advice extended during test road
construction.
v
SUMMARY
Test roads were constructed near El Paso, Buffalo and Brownsville.
All test roads were designed as statistical experiments such that future
analysis of effects due to asphalt-rubber formulation could be
detennined. Asphalt-rubber was formulated using various rubber
concentrations, rubber types, digestion conditions, and interlayers were
applied at various binder application rates. In addition, aggregate
grade was varied at Brownsville, and single and double binder
applications were studied.
Laboratory evaluation of binder properties provides a basis for
future correlation between laboratory and field performance.
vi
- IMPLEMENTATION STATEMENT
Laboratory test results obtained in this study by four new or
modified test procedures should provide information necessary to develop
. a state sPecification for asphalt-rubber based on Performance• However,
until fieln perfonnance is established, it will be difficuit to establish
specification requirements based on laboratory-test results.
However, observations and tests made in the fi.eln ourine'l construction
of the three test roads, along with experience gained on previous and
concurrent asphalt-rubber research, allowed preparation of a modified
seal coat design procedure recannended for construction of asphal t~rubber
seal coats and interlayers. Also, an updated specification is included
which is reccmnended for future asphalt--rubber construction.
vii
TABLE OF CONI'ENI'S
OBJECTIVES. • • • DISCLAIMER. • • • .ABS'I'RACr •. . • • • • ~s .• ~y •••••••••• IMPLEMENTATION STATEMENT. TABLE OF CONI'ENTS • • • • • LIST OF TABLES. • • • • • • • • LIST OF FIGURES
CHAPTER
I
II
III ·
IV
v
VI
INI'RODUCTION • History ..• Scope. • • .
~~ ..... . El Paso Test Road. Buffalo Test Road. • • Brownsville Test Road.
EXPERIMENT DESIGN. • • • • • • • • • • • • • • • • El Paso Test Road - Field Responses ••• El Paso Test Road - Laboratory Responses Buffalo Test Road - Field Responses .•.. Buffalo Test Road - Laboratory Responses • Brownsville Test Road - Field Responses •..• Brownsville Test Road - Laboratory Responses .
SITE SElECTION • . • • • El Paso Test Road. . Buffalo Test Road. •
TEST ROAD CONSTRUGriON • • • • El Paso - Preconstruction. • El Paso - Construction • • . Buffalo - Preconstruction. • Buffalo - Construction • . . . Brownsville - Preconstruction. Brownsville - Construction
lABORATORY TESTS • • • • • • .
PAGE
. . . . ii .. iii
iv v
vi • • vii
.viii X
... xii
1 1 2
4 4
11 16
18 19 21 24 27 28
30 31 34
39 39 44 53 57 59 64
. Torque Fork MiXer. • • • . . • • . . • • . 71 71 74 76 81
Haake Viscometer • • • • • . • • . . • • • Force Ductility ••..•.....••• DoUble Ball Softening Point. • • • • .
viii
TABLE OF OONTEN'IS (continued)
CHAPI'ER
VII
VIII
IX
X
LAIDRA'IDRY TEST RESUL'IS. • • • • 'Ibrque Fork Mixer • • • . • • • • • • • • • • • Force Duct i 1 i ty • • • • • • • • • • • Double Ball Softening Point •••••
AN.AI...YSIS • • • • • • • • • • • • • • • • • • • Rubber Concentration • • • • • • • • • Digestion Level ••• , •••• Rubber 'I'{pe • • • • • • • • • • • • • • • • Combined Effects: Concentration and Digestion • •
CONCLUSIONS •••• . ·• . . RECOMMENDATIONS. . . . .
REFERENCFS • • • • • • •
ADDITIONAL REFERENCES . .. . . APPENDIX A. APPENDIX B. APPENDIX C. APPENDIX ·o. APPENDIX E.
Photolog Surrmary - El Paso. • • • • • Photolog Surrmary - Buffalo and Rrownsville Force Ductility comPuter Program. • • • • • • • Force Ductility/Double Rall Softening Point Data Specification for Asphalt~Rubber Seal Coats and Interlayers • • • • • • • • • • • • • • • • • • •
ix
. . ..
PAGE
85 85 94 99
107 107 115 126 132
139
146
148
151
161 176 193
. 212
. 253
Table
1
2
3
4
5
6
7
R
9
10
11
12
13
14
15
16
17
18
19
20
21
LIST OF TABLES
Asphalt Properties • • . • .
Rubber Types . • . . . . • . .
El Paso Rubber Gradations
Rubber Properties . • . • .
Mineral Aqgregate Properties.. .
Asphalt.Concrete Properties •.
El Paso Photolog Locations • • .
Pavement Rating Deduct Values
. •./ .
El Paso Preconstruction Pavement Rating Scores •.
El Paso Mixing Observations and Test Results •.
El Paso Application Quantities.
El Paso Overlay Thicknesses
Buffalo Photolog IDeations •.
. .. .
Buffalo Preconstruction Pavement Rating Scores.
Buffalo Mixing Observations and Test Results ..•••
Buffalo .Application Quantities • • • •
Buffalo OVerlay 'Ihicknesses . • . •
Brownsville '!est Section Materials • •
Brownsville Photolog Locations •••.
Brownsville Ereconstruction Pavement Rating Scores •.••.
Brownsville '!est Road Aggregate and Binder Application
Rates . . . . . . . . . . • . . ~ • . . . . . . .
22 Theoretical and Measured Asphalt-Rubber Relative
Viscosity . . . . • • . . • • • • . . • • • • . .
23 Statistically Significant Results of ANOVA for
Force Ductility Test Measurements of El Paso Lab
Mixes . . . . . . . . . . . . . . . • . . . . .
24 Statistically Significant Results of ANOVA for
Force Ductility Test Measurements of El Paso Field
Mixes • • . . • • . • . • • • • • .
25 Results of Newman-Keuls Analysis of Force Ductility
Test Measurements for El Paso Lab Mixes . • . • • .
X
PAGE
5
6 7
9
13 14 40 42
43 48 52
54
55
56
58
62
63
65
66 67·
69
70
95
95
96
LIST OF TABLES (continued)
Table
26'
27
Results of Newman-Keuls Analysis of Force Ductility
Test Measurements for El Paso Field Mixes • • •
Statistically Significant Results of AOOVA for
Force Ductility Test Measurements of Buffalo Lab
Mixes . . . _ • . . . . . . . . . . • . . • . • .
28 Statistically Significant Results of M!lJVA for
Force fuctility Test Measurements of Buffalo Field
PAGE
97
98
. Mixes • • • . • • • • •. - • • • • • • . • • • . . • • • 98
29 Results of Newman-Keuls Analysis of Force Ductility
Test Measurements for Buffalo Field Mixes ~ • • . • • • . • 100
30 Results of Newman-Keuls Analysis of Force Ductility
31
32
Test Measurements for Buffalo Lab Mixes • • • · • • . •
Results of Newman-Keuls Analysis of Softening Point
Test Measurements for Buffalo Lab Mixes • • • • • • •
Results of Newman-Keuls Analysis of Softening Foint
101
103
Test Measurements for Buffalo Field Mixes •.••••••• ·103
33 AOOVA Force Ductility and Softening Foint, Brownsville
Lab Mixes •• . • 104 34 Newman-Keuls, All Parameters, Brownsville Lab Mixes • • 106 ·
35 Test Responses lJudged Significant by ANIJVA •••••••• 108
xi
FIGURE
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
LIST OF FIGURES
Rubber Gradations • . • . . . . • .
Aggregate Gradations
Asphalt Concrete Resilient Modulus. . • • • .
El Paso Field Response Experiment •.•...
El Paso Lab Response to Field Mixed Material.
El Paso Lab Response to Lab Mixed Material.
Buffalo Field Response Experiment • . • • • •
. . . . .
Buffalo Lab Response to Lab Mixed Material ....•.
Buffalo Lab Response to Field Mixed Material. •
El Paso Test Road Incation. .
El Paso Test Sections • • • . . . • .
Buffalo Test Road IDeation • • • •
Buffalo Test Sections • .
Brownsville Test Sections
Pavement Rating Form
Asphalt-Rubber Specific Gravity
El Paso Asphalt-Rubber Viscosity
18 El Paso Asphalt-Rubber Temperature fJJSS After
19
20
21
22
23
24
25
26
Application • • • • • • • . • • • . • • • . • •
Buffalo Asphalt-Rubber Viscosity. • . . • . •
Buffalo Asphalt-Rubber Temperature Loss After
Application . • · • • .
Torque Fork Mixer
Haake Viscometer.
Force-Ductility Testinq Machine •
AS'IM 0113 Ductility Mold. . . .
Force-Ductility Mold. . . • • • .
Force-Ductility Testing Apparatus .
. .•
PAGF.
8
12
15 20 22
23 25
26
29
32 33
35 36
38
41 47
49
51 60
61 72
75
77
78
78
80 27 Representative Asphalt-Rubber Stress-Strain Curve 82
28 Double Rall Softening Point Apparatus . • • . . . • • 84 29 .El Paso Torque Fork Output-22 Percent Rubber. 86
30 El Paso Torque Fork Output-24 Percent Rubber ..
xii 87
LIST OF FIGURES {continued)
FIGURE
31
32
33
34
35
36
El Paso Tbrque Fork OUtput~26 Percent Rubber.
Relationship Petween VTF and VB
El Paso 'Ibrque Fork Viscosity •
Rubber Volt.me Change at 400F. •
Effect of Rubber Concentration on Failure Strain
Effect of Rubber Concentration on Asphalt Modulus
37 Effect of Rubber Concentration on Asphalt-Rubber
Modulus • . • • • • • • • • • • • • • • • • • • •
38 Change in Stress-Strain Curve Due to Increasing
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
Rubber Content. • • • • • • • • • • • • • •
· Effect of Rubber Concentration on Softenirg R:>int •
Effect of Digestion Level on Failure Stress •
Effect of Digestion r~vel on Failure Strain
Effect of Digestion Level on Asphalt Modulus.
C'.,el Penneation Chrqnatoqraphy Fesul ts • • • •
Effect of nigestion I2vel on Asphalt-Rubber Modulus •
Effect of Digestion Level on Curve Area • • •
Effect of Digestion Level on Soften:i.nq Fbint. •
Effect of Rubber TYPe on Failure Stress • •
Effect of Rubber TYPe on Failure Strain •
Ef feet of Rubber TYPe on Curve Area • • • • • •
Effect of Rubber TYPe on Asphalt Modulus ••
Effect of Rubber 'JYpe on Asphalt.;..Rubber Modulus
Effect of Rubber Concentration and Digestion
Level' on. Asphalt Modulus. • • • • • • • • • •
Effect of Rubber Concentration and Digestion
Level on Asphalt-Rubber Modulus • • • • • • •
Effect of Rubber Concentration and Digestion
Level on Softening Foint of Lab Mixes • • • • -
55 Effect of Rubber Concentration and Diqestion
Level on Softening Point of Field Mixes
xiii
PAGE
88 89 91 93
110 111
112 i
113 114 116 117 119 121 122 124 125 127 128 129 130 131
133
134
135
136
LIST OF FIGURES (continued)
FIGURE
56 F.ffect of Rubber Concentration and Diqestion
Level on Failure Strain. • • • • • • •
57 Relationship Between Viscosity and Rubber
Content. • • • • • • • • • • •
58 Percent Embedment Determined by Mat 'Ihickness .•
xiv
PAGE
138
143 145
CHAPTER I
INTRODUCTION
Histqcy
Ground tire rubber has been used as an additive in various types of
asphalt pavement construction in recent years. The use of rubber is an
attempt to input additional elasticity to paving materials.
A blend of paving asphalt ce~nt and ground tire rubber is called
"asphalt-rubber". Rubber content of this blend is 18 to 26 percent by
total weight of the blend (1). The blend is formulated at elevated
temperature to promote chemical and physical bonding of the two
components. Various petroleum distillates are sometjmes added to the
blend to reduce viscosity and promote workability.
Asphalt-rubber binders have been used in a number of Civil
Engineering applications, including chip seals, interlayers and asphalt
concrete. An asphalt-rubber seal coat sandwiched between an existing
cracked asphalt concrete pavement and new asphalt concrete overlay is
called an asphalt-rubber "interlayer" (2). Observations of field
installations of over two hundred separate pavement sections containing
asphalt-rubber have indicated that asphalt-rubber bound materials reduce
the occurrence of reflection cracking when used as interlayers in certain
applications ( 1 ).
Asphalt-rubber has· been used in pavement rehabilitation systems where
reduction of reflection cracks is desired. However, much of the
asphalt-rubber use is in seal coat construction (1,4). This is due to
the ability of asphalt-rubber to retain aggregate chips under relatively
high traffic compared with conventional binders. The good chip retention
is due to higher allowable initial embedment of aggregate chips. Higher
initial embedment is possible because of the relatively hiqh viscosity of
asphalt-rubber binders canpared with conventional.binders. These high
embedment depths and correspondinq ~igh binder application rates also aid
1
in waterproofing substrate pavement layers which also aides in prolonging
pavement service life.
Historically'· the design and construction ot asphalt-rubber seal
coats and interlayers has been identical, although recent research
sugqests modifications of old techniques are .iustified ( 3).
Past construction techniques for seal coats and interlayers specified
the quantity of asphalt-rubber binder with little regard for materials
properties of the mineral aggregates to be used. Field surveys conducted
throughout the United States ( 1) , and in 'Iexas ( 4) , indicate performance
of asphalt-rubber seal coats and interlayers could be ~roved by
following an engineering design procedure. The design procedure is an
adaptation of an existing procedure developed for conventional seal coats
(26) with provision for higher initial aggregate embedment. ·These
studies (1,4) show that although reflection cracking is red~ced in some
pavements, it may be at the expense of increased flushing that this
desirable cracking performance is achieved. These researchers believe
engineering design of these systems will help balance performance between
flushing and cracking. Many types of asphalt-rubber fonnulations are
possible due to a wide assortment of constituents available. Evidence
suggests certain asphalt-rubber blends may produce undesirable results in
the laboratory (5). Although some data are available regarding
performance of asphalt-rubber in the laboratory (5,6,7,8,9) a correlation
between laboratory data and field performance has not been developed.
The purpose of this research was to design and construct three field
test pavements containinq asphalt-rubber interlayers. Pavement condition
surveys conducted prior to interlayer construction provide data regarding
initial pavement condition. These oata establish a datum which will
allow future comparison of field performance for the various types of
interlayer blends placed at each test road.
2
Laboratory tests were performed on blends of asphalt-rubber prepared
in the field as well as blends prepared in the laboratory. These data
form the basis for future correlations between laboratory properties and
field performance.
Three field test pavements were constructed as part of this research.
One test pavement was constructed in the east and westbound travel lanes
on Interstate Highway 10 east of Rl Paso, Texas for approxnnatelv nine
miles between. FM 34 and the McNary interchange. 'Ibis pavement will be -..:._'-
referred to as the "El Paso Test Road".
The second. test pavement was constructed in the northbound travel
lane of Interstate Highway 45 from the leon-Freestone County Line north
to the u.s. 84 overpass, a distance of approximately eighteen miles.
This pavement will be referred to as the "Buffalo Test "Road".
Test road number three was constructed in the north and southbound
lanes of State Highway 4 from the International Bridge north
approxnnately two miles. This pavement will be referred to as the
"Brownsville Test Road".
3
CHA.PrF.R I I
MATERIALS
El Paso 'Ies t Road
Asphalt cements used in the preparation of asphalt-rubber binders and
asphalt concrete was obtained from the Chevron refinery in F.l Paso,
Texas. These asphalts meet the Texas State Department of Highways and
Public Transportation (SDHPr) specification (12) requirements for AC-10
and AC-20 viscosity graded materials as shown in Table 1.
'Ihree sources of rubber were used to produce asphalt-rubber binders
investigated at the El Paso Road. These rubber materials were obtained
from the suppliers shown in Table 2. Sieve analysis of rubber was
accanplished following a m:xlified AS'IM Cl36 procedure ( 10). The
procedure was changed by lightly rubbinq the rubber particles by hand on
each sieve to prevent rebound from the sieve surface. Undue force was
not applied using this procedure to avoid pushing particles through the
sieve.
It was desired to estimate the precision of the IT\OO.ified sieve
analysis procedure. Therefore, ten random sieve analyses were performed
by the same operator on each of the three rubber types. The percent
rubber passing each sieve was measured and confidence intervals have been
established for gradation of each rubber type based on averaqe and
standard deiration for percent passing each sieve size. Gradations with
95 percent confidence limits appear in Table 3. Average gradation for
each rubber type is plotted in Figure 1. Further characterization of
each rubber type followinq AS'lM procedure D297 (11) provides data
relating to physical and chemical properties as shown in Table 4.
Dolomite mineral aggregates used for construction of interlayer and
asphalt concrete were obtained from the Esperanza Pit, Esperanza, Texas.
Interlayer aggregates were precoated with approximately one percent
Chevron AC-20 and stockpiled prior to application.
4
Table 1. Asphalt Cement Properties.
AC-10 AC-20 Properties Asphalt Spec Asphalt Spec
El Paso Buffalo Brownsville Min. Max. El Paso Buffalo Brownsville Min. Max.
Viscosity, 140F poises 1048. 868 930 1000+200 1860 1755 1792 2000+400
Viscosity, 275F stokes · 2.9 2.8 2.9 1. 9 - 3.8 3.5 3.7 2.5
Penetration, 77F, lOOg, 5 sec 92 150 136 85 - 69 70 88 55
Fl a·sh Point U'1 C.O.C., F 600+ N/A 530 450 - 600+ 5·95 582 450
Specific Gravity, 77F 1.010 1.017 1 .022 N/A 1.012 1.013 1.024 N/A
Tests on residues from thin film oven test:
Vi s cos i t y , 140 F poises 2257 2445 2228 - 3000 4146 4485 3431 - 6000
Ductility, 77F, 5 ems per min., ems 141+ 141+ 141+ 70 - 141+ 141+ 1:41+ 50
Table 2. Rubber Types.
Rubber
A
B
c
D
E
El Paso Test Road
Source
Genstar Conservation Chandler, Arizona
Atlas Manufacturing Los Angeles, CA
Midwest Elastomers Wapokonetta, Ohio
Source Designation
Cl04
TPO 44
N/A
Buffalo/Brownsville Test Roads
Gens tar Conservation, Chandler, Arizona
Baker Rubber, South Bend, Indiana
6
Cl06 ·
lMAT-20
Manufacturers Designation
Whole Tire, Vulcanized, Ambient Grind
Tread Tire, Vulcanized, Ambient Grind
Whole Tire, Vulcanized,· Cryogenic Grind·
Whole Tire, Vulcanized Ambient Grind
High Natural Rubber Content, Vulcanized, Ambient Grind
Table 3. El Paso Rubber Gradations.
Percent Passing
Rubber Rubber Rubber Sieve A B c No. 8 100 100 100
No. 10 100 100 99 + 0.5
No. 16 65 + 5.6 38 + 2.1 67 + 3.9
No. 30 2 + 0.3 8 + 0.6 8 + 1.1
No. 40 0.5 + 0.4 4 + 0.4 3 + 0.9
No. 50 0 3 + 0.4 1 + 0.6
No. 100 0.4 + 0.5 0.2 + 0.4 !
No. 200 0 0
7
00
C)
c •r-V) V)
ltJ c.. ~ c QJ u ~ QJ c.. .-
"' ~ 0 t-
1 00 0 I 1 I I I 'JR • ' 90
f{
80 /J D
70 I --6-- Rubber A} -__ -o- Rubber B El Paso _
60 1 -o- Rubber C ~ Rubber A-Buffalo -
50 1----+--l---1----+---+--l---lf-
401 ____ ~~~~+-~~U-~--+4----~----~+--+~~
, I7 rJZ 30 I J Jl I
- L J 'I J .20 I tf ~
j~ I .1 I J. __,I / lJ'I 1 __l 1 __l I I I 101 I .~ ~~ 0;.
No. 200
~
80 100
...J.
40 50 30 16
10 8
Sieve Size
Figure 1. Rubber Gradations
1/2 11 1" 4 3/8 11 3/4 11 1 1/2 11
Table 4. Rubber Properties.
El Paso
D _pa_ . _LJL~--·· Specific Gravity 1.165 1.153 1.150
'Ibtal Extract, % by 15.45 19.47 24.50
weight
Ash, % by weight 5.71 3.49 2.41
Free Carbon, % by 29.21 30.75 31.31
weight
Total Sulfur, % by 1.17 1.02 1.10
weight
Rubber R:>l ymer:
Natural Rubber,
% by weight 30 20 0
Styene butadiene, %
by weight 60 80 55
Polybutadiene, % by
weiqht 10 0 45
... ~ ..... -- ... ............... ..... .. ....... 100 100 100
Rubber Hydrocarbon, %
by volt.une 60.92 55.R9 50.76
9
Table 4. Rubber Properties. (Continued)
Buffalo Brownsville
n D/P.* .PL~:-- ----... ... Specific Gravity 1.160 1.48 1.15
Total Extract, % by 15.41 12.75 13.27
weight
Ash, % by weiqht 5.68 4.86 s.o3
Free Carbon, % by 29.00 2R.35 28.53
weight.
Total Sulfur, % by 1.15 1.17 1.18
weight
Rubber Fbl ymer:
Natural Rubber,
% by weight 30 61 54
Styene butadiene, %
· by weight 60 35 40
Polybutadiene, % by
weight 10 4 6 ............... ---
100 100 100
Rubber Hydrocaroon, %
by volume 61.02 58.46 58.95
*Combination of Rubber Types D&E as shown in Table 2.
'10
Particle size qradations of interlayer and asphalt concrete
aggregates appear in Fiqure 2. Both materials conform to Texas SDHPT
.Item 302 Grade 4·and Item 340 TypeD specification l~its, respectively.
·Physical properties of mineral aggregates conform to Texas SDHPT
specifications as shown in Table s.
Samples of the asphalt concrete overlay were obtained by coring each
test section approximately two weeks after construction. Characteristics
of the overlay asphalt concrete are as shown in Table 6. Figu.re 3
indicates the variation of asphalt concrete resilient modulus with
temperature.
Buffalo Test Road ......... .. -' .....
Asphalt used for asphalt-rubber blending was an AC-10 asphalt cement
supplied by 'Texas Fuel and Asphalt, Corpus Chris.ti, Texas. f\Sphalt for
asphalt concrete production was an AC-20 asphalt cement supplied by
Trumbull A.sphal t of Houston, Texas. These asphalts meet the Texas SDHPT
specification requirements for ~C-10 and AC-20 viscosity graded materials
as shown in Table 1. A flux oil, Sundex 790, from Sun Oil Corporation,
Houston, Texas, was blended with the AC-10 asphalt prior to blending with
rubber.
One rubber source was used to produce the asphalt-rubber placed on
the Buffalo '!est Road. 'This material is described as Rubber A
Designation ClO~ in Table 2. This rubber has the same chemical
properties as Rubber Type A Designation Cl04 used at the. El Paso '!est
Road. However, particle size gradation differs. Sieve analysis of the
rubber is shown in Figure 1. Note the finer size gradation of the
Buffalo Type A rubber compared with El Paso Type A.
Limestone mineral aggregates used for construction of interlayer and .___;
asphalt concrete were obtained from the Yelberton Pit near Mexia, Texas.
Interlayer aggregates were precoated with approxnnately 0.50 percent
AC-20 immediately prior to application.
11
100 I I I I I I I I I I I - I ,-
I I 1 I I 1 } ~ J ITf I 90 -, I I l - 1 I I IJ I I
80
70
I
I ' I
-6- E1 Paso Aspha 1 t Concrete I I ;: • Buffalo Asphalt Concrete
--o-- El Paso Interlayer (Grade j ') , ) V r
--•-- Buff Ala Interlayer (Grade a) 1 /c ~ 0')
c 60
.,... V'l
I / I I
if/ I I
I V'l ttS Ar I I a.
50 ....., c OJ
40
~
u N
S- ,. OJ a.
$ I I // I I
~ v I . •
~ v ~ I . r-- 30 ttS ....., 0
20 t-
.......... ~ J I
/ v I I v~ v I
It
v v I II
10 ..,... ~ :/ 1
~~ ~ loT
' /
0 v ct>-~----' ~ ...... -V" --
80 40 10 1/4 11 1/2 11 1" No. 200 100 50 30 16 8 4 3/8 11 3/4 11 1-1/3"
Sieve Size
Figure 2. Aggregate Gradations
~ (..,..)
Table 5. Mineral Aggregate Properties
''. Seal Coat
El Paso Buffalo Brownsville
'lest Grade 4 Grade 3 Grades 3 & 4
Unit
Weight,pcf 84.fi 81.5 N/A
Thx-404A ...... L. A.
Abrasion,% 21 33 N/A
Thx-410A •
Fblish
Value,% 35 45 N/A
Thx-438_A
Decant.,% 0.4 0.8 .3 Thx-217F,II
Plasticity N/~. N/1\ N/A Index
Thx-106E
Sand N/A N/A
Equivalent -~------~--- ~
......... t .. • • t .... *' .• ... t I . Ff ......
Asphalt Concrete
Spec El Paso Buffalo Brownsville Spec
(12) TypeD Type c TypeD (12) ....
35, N/A 91.4 85.2 N/A min
I I I I -, I
40, I
35, I
21 33 N/A max I
max
N/A 35 45 N/A N/A
I
5, o.R. 0.8 o.s 1,
max max
N/A 1 1 1.5 6, ro.ax
N/A N/A 45, N/A 60 min __ ___.__.~
Table 6. Asphalt Concrete Properties.
Hveem Stability (Texas Method)
Indirect 'Iensile Modulus, 77F,
psi x 103
Indirect Tensile Modulus after
Lottman Freeze-Thaw, 77F,
psi x 103
Resilient Modulus, 77F, psi x 103
Resilient Modulus after Lotbman
Freeze-'Ihaw, psi x 103
Asphalt Content, % by weight
Unit weight, pcf
~sorbed Asphalt, %
Effective Asphalt, %
VMA, %
Air Voids, %
F.l Paso
33
34.9
30.2
328
242
s.o
144.7
1.1
3.9
14.6
s.s
14
Buffalo --19
11.8
12.0
266
188
4.9
139.5
0.9
4.0
19.6
9.2
Brownsville Jjzl .... ~
46
10.4
12.4
137
155
5.4
136.9
N/A
N/A
N/A
9.4
2500
-o- ~1 P~so
--tr- Buffalo
2000 -o- Brownsville
rt")
0 )(
C/)
c. 1500 ,. V) :)
:)
\J 0 ~ -c: 1000 QJ
·v; QJ
a::
500
25 50 75 100
Temperature, F
Figure 3 . Asphalt Concrete Resilient Modulus
15
Particle size gradations of aggregates are shown in Figure 2.
Materials conform to Texas SDHPT Grade 3 Item 302 seal coat and Type C
Item 340 asphalt concrete specification limits, respectively, as shown in
Table 4. Physical properties of the l~stone are shown in Table s.
Core samples of the asphalt concrete overlay were obtained within
each test section approxnmately two weeks after construction. Laboratory
properties of the asphalt concrete are summarized in Table 6 and
represented graphically in Figure 3.
Brownsville Test Road zt t'., d <st• rd stcrlr
Asphalt used for asphalt-rubber blending was an AC-10 from Texas
Fueld and Asphalt, Corpus Christi, Texas. ~n AC-20 was obtained from. the
same source for asphalt concrete production. '!hese asphalts meet Texas
SDHPT specification requirements as shown in Table 1. Sundex 790 from
Sun Oil Corporation was blended with the AC-10 asphalt at 6 percent by
volume. Control sections were placed with non-modified AC-10 and polymer
modified emulsion, designated HFRS-2, from Texas Emulsions, Austin,
Texas.
The rubber used to produce the asphalt-rubber was a blend of 60
percent 'IYf>e A and 40 percent Type B as shown in Table 2. Properties of
the blended rubber appear in Table 4. Sieve analysis of this rubber
blend appears in Figure 1.
Mineral aggregates for asphalt concrete were obtained from the San
Juan Plant. Seal coat aggregates were sampled from the Fordyce Company,
Spaulding Pit. ApproxBnately 1 percent lUne fvam Redland WOrth
Corporation was added to the asphalt concrete.
Particle size gradation of aggregates appear in Fiqure 2. Asphalt
concrete aggregates conform to Texas SDHPT Type D, and interlayer
· agg.regates·conform to Grades 3A and 4, respectively. Physical properties
of aggregates appear in Table 5.
16
Laboratory properties of core samples obtained by District 21
personnel appear in Table 6 and ·Figure 3.
17
CHAPI'ER I I I
EXPERIMENT DESIGN
The following discussion relates to the statistical design of two
experimental test roads. Subscripts within the mathematical models are
associated with main factors and replicates.
A major portion of this research was dedicated to establishinq
statistically designed field and laboratory experiments which could form
the basis for future correlations between field performance and
laboratory test results.
This experiment was designed as a Latin Square ( 21) with three
samples per treabnent. The statistical model for the analysis of this
design is formulated as follows:
where:
Y .. k = ll + R • + C . + Ak + e .. k lJ 1 J lJ
Y .. k =response to ith rubber, ith concentration and kth lJ -application rate.
ll = effect on response of the overall mean
R; = effect on response of the ith rubber,
i = 1,2,3
Cj = effect on response of the ith concentration,
j = 1,2,3
Ak ~ effect on response of the kth application rate,
k = 1,2,3
eijk = random error
Note: This Latin Square was designed without replication. Therefore,
estnnation of interaction effects is not possible as the model above
reflects. As a first approxnnation, this experiment estDn8tes main
factor effects only, and assumes no interactions.
18
Levels of the independent variables are as follows:
I. Rubber Type, Ri
A. Type A (Table 2)
B. Type B (Table 2)
c. 1'fpe C (Table 2)
II. Rubber Concentration, %, c;
A. 22
B. 24
c. 26
III. Application Rate, gsy, AK
A.·0.35
B~ 0.40
c. 0.45
The matrix arrangement shown in Figure 4 depicts all combinations of
variables investigated for field response at the El Paso Test Road.
TWo experiments were designed for this phase of the research. One
deals with asphalt-rubber material prepared in the field and the other
deals with asphalt-rubber prepared in the laboratory. Both expernments
are full factorial designs with fixed factors and three.replicates.
Models for analysis of these respective experiment designs are as
follows:
Field Mixed Asphalt-Rubber
Y •• k = 11 + R . + C . + RC • . + e .. k lJ 1 J lJ lJ
where terms are as indicated previously and RCij represents the
interaction effect of the ith rubber and jth concentration. A
19
Rubber Concentration, c. J
22 24 26
c B A
L(') Section Section Section
('V') 2 9 8 . 0
~ <(
.. B QJ
A c ~ ttS Section · Section Section 0::::
0 c lid- 4 1 6 0 . .,... 0 ~ ttS u .,...
A c B r--~ ~
<C Section Section Section LO lid- 5 7 3 . 0
'Figure 4. El Paso Field Response Experiment
20
'Rubber Type, R;
Control (No Interlayer)
Section 10
matrix representation is shown in Fiqure s.
Laboratory Mixed Asphalt-Rubber
11 + R1• +C.+ Dk .+ RC .. + RD.k + CD.k + RCK. 'k +e. 'k J lJ 1 J lJ · lJ m
where:
Dk = effect on response of the kth
digestion condition, k ~ 1,2,3
and other terms are as before with interactions
occurring for all combinations of main effects.
Figure 6 is a matrix representation of this
experiment.
Three digestion conditions were produced in the laboratory. 'Ihese
digestion conditions were varied from low to rroderate to high· to provide
a range from which simulation of field digestion could be approxnnated.
The basis for this lab variation was an effort to provide asphalt-rubber
lab mixes with properties of field prepared mixes.
Buff?-~.9. Te~~ :Road - Field Re~~nses
This experiment was designed as a full factorial with two fixed
factors and two replications. 'The model for analysis of this design is
as follows:
Y. 'k = ll + C. + D. + CD .. + e1·~J'k l.J l. J l.J
where terms are as before.
Levels of the independent variables are as follows:
I. Concentration of Rubber, Ci
A. 18
21
Rubber, Ri
A B c
- - -N N - - -
- - -.,.., u
" c 0
•r-......, - - -., "'" s- N - - -......,
c -- - -Q) u c 0 u
- - -1..0 N - - -
- - -
'Figure 5. El Paso Lab0ratory Response to Field Mixed Material
22
N (..,..)
Qlt ). ).
A B c o_, ~
() ('
.f !./.
22 24 26 22 24 26 22 24 '
Low - - - - - - - -- - - - - - - -- - - - - - - -
Med - - - - - - - -- - - - - - -- -- - - - - - - -
High - - - - - -' - -- - - - - - -- - - - - - - -
· . Figure 6. El Paso Laboratory Response to Laboratory Mixed Material
26
---
--· -
---
B. 22
II. Digestion, Dj
A. I.ow
B. High
In this experiment, rubber type and application rate are held
constant. The resulting four treatments are replicated providing eight
experimental test sections. Four .additional test sections were included
as control sections. TWo sections were constructed using a conventional
asphalt cement as the interlayer binder and the other two sections
contain no interlayer.
This experiment was designed to evaluate laboratory responses of
field mixed and laboratory mixed asphalt-rubber materials as in the F.l
Paso experiment. The experiment is a replicated, full factorial with
fixed factors analyzed according to the model appearinq below:
Y .. k = 1..1 + C • + D . + CD . . + e .. k 1J 1 J 1J 1J
where terms are as previously described.
·The matrix representation of the field and
laboratory experiments for this model appear
as shown in Figures 7 and 8.
The model used for analysis of the laboratory response to field
prepared asphalt-rubber is shown below:
y ijkt = 1..1 + C. + D. + Rk + CD .. + CR.k + DR.k + CDR .. k + 1 J 1J 1 1 1J
where terms are as previously described and,
24
-'= 0') .,.., ......
c ::I: .. c 0 ...... ...., U) QJ 0') ...... c ~
0 -I
Concentration, %
18 22
1 7
8 12
9 6
11 10
Controls (AC Binder)
2
5
(No Interlayers)
3
4
Note: Numbers shown are test section numbers noted on Figure 13.
Figure 7. Buffalo Field Response Experiment.
25
Concentration, %
18 22
- -3: - -0 _J --
s:::: - -0 .,....
+-J -c - -(/) QJ QJ ::E Ol - -.,....
Cl
--..s:::: - -Ol .,....
::I: - -
Figure _8. Buffalo Laboratory Response to Laboratory Mixed Material
26
~ = effect on response to kth field replicate, k = 1,2
This third main effect is added to the roodel such that judganent .
regarding replicate batches of fieldndxed asphalt-rubber is possible.
Matrix representation of this experiment is as shown in Figure 9. Field
replicates of each treattnent were fabricated .t.o judg~ variability within
each material type. For example, test sectiorts 1 and. 8 represent two
separate batches, or truck loads, of High Dig~stion, 18 percent,
asphalt-rubber. These replicates will allow future CCJll>arison of field
perfonnance within a given treatment such that variability can be judged
between treatinent types. In this study' it was desired to see whether
·laboratory responses differed significantly for replicate materials
fabricated in supposedly the same manner.
Brownsville Test Road - Field Responses
The Brownsville Test Road was designed to evaluate field perfonnance
of two aggregate grades in single and double applications as interlayers.
Asphalt-rubber fonrulation was not varied in this experiment. Control
sections are canposed of inter layer binders of polymer modified asphalt
and conventional asphalt cement.
All combinations of interlayers applied at the Brownsvil~e Test Road
are described in the following table:
27
Binder Application
Single
Single
Single*
Double
Double
Double
Double
Double
Binder Type
A-R
A-R
A-R
A-R
A-R
A-R
AC
Polymer
*Grade 4 aggregate was applied two
over one application of binder.
'Ibp Aggregate
Grade
3
4
4
3
4
4
4
4
layers deep
Browps~ille Test Bead ~ Laborato£¥ Reppgns~
in one
Bottom ~greg ate
Grade
N/A
N/A
4
3
3
4
3
4
application
The asphalt-rubber binder at Brownsville Test Road is composed of the
same asphalt and n1bber as Buffalo Test Road for the Genstar/Baker blend
except Brownsville contains a 60:40 ratio of Genstar to Baker canpared
with a 50:50 ratio at Buffalo.
'nle laboratory mixes are compared for low, moderate and hiqh
digestion, similarly to El Paso and Buffalo mixes.
28
29
"'0 QJ X .,... :E
"'0 ...-QJ .,...
L1..
0 .f-)
QJ (/)
s:::: 0 0. (/) QJ
0::::
~ 0 .f-) ttl s... 0
.J:l ttl _J,....
oltl ,.....,... caS... 4-QJ 4-...., :lea co:::E:
CHAPTER IV
SITE SELOCTION
Location of both field test roads was accomplished in cooperation
with the Texas SDHPT. A list of sites was obtained from highway
districts planning asphalt-rubber interlayer construction and from this
list potential test sites were selected. Criteria used to judge the
adequacy of sites are listed in order of importance below:
1. Willingness of district and contractors to participate
in experiment.
2. Size of proiect.
3. Ttme until next planned rehabilitation.
4. Pavement substructure uniformity.
5. Overlay thickness and uniformity.
6. Distress unifo~ty.
A contract had been awarded on the project which would becoma the El
Paso Test Road when initial contact with the El Paso Highway District was
made. Since significant changes in the original contract were required
to accamodate the planned experiments, it was crucial that a cooperative
spirit exist between highway department, contractor, and research
personnel. Planning the Buffalo Test Road began before there was a
contract between the highway department and a contractor. Therefore,
requirements of test section construction were included in iob specifications and subject to competitive bidding.
A full distributor of asphalt-rubber was desired for use in
application.of each test section for both test roads. This was desirable
for reasons listAd below:
1. A more representative hlend of asphalt-rubber could be expecteo
compared with partial loads,
2.- Test section length·of approximately one lane-mile resulted from
app~ximately 4200 gallon distributor loads. These lengths provided
transitions before and after the 1500 feet of photoloqs contained in· each
30
test section. 'Ihis further enhanced the_ potential for representative
materials placed over photologs.
3. Production rate was not _appreciably slowed. 'Ihis enhanced the
desired cooperative spirit between·contraGtor and research personnel.
Project size was an important factor for both test rqads since it was.
desired to place test sections in lanes.having consistent traffic volumes
and loads. Both pro;ects were of sufficient length to accomodate
app~ximately nine lane miles for the El Paso Test Road and over ten lane
miles for the Buffalo Test Road.
El Paso Test Road
'Ihe El Paso Test Road is part of Texas Project FR-10-1 ( 168)079
located on Interstate Highway 1U (IH-10) in Hudspeth County,
approxDnately 80 miles east of El Paso between the McNary interchange and
FM 34 as shown on Figure 10. Test sections are each approx~ately 0.90
mile in length in the travel lanes as shown in Figure 11.
Original pavement structure for eastbound lanes was u. s. Highway 80
consistinq of a 20 foot wide pOrtland cement concrete pavement
constructed in 1932. Conversion of the original highway to th~
interstate system in 1963 added westbound lanes consisting of 6 inches
dense graded asphalt concrete over n inches cement treated base and 6
inches cement tr~ated subqrade. An overlay of original portland cement
concrete pavement in 1963 consistert of 6 inches dense graded asphalt
concrete in which 3 inch by 6 inch Number 10 \Yelded wire fabric was ·
embedded in the lower 1-1/2 inches.
Distress consisted of slight to severe transverse cracking at randan
intervals, and canbinations of lonqitud:i.a1 and alligator cracki.nq
distributed throughout.
Traffic on the El Paso Test Road consisted of a total traffic volume
of 7900 average daily traffic (liDT) in 1983. Truck volume was
31
El Paso
FM34
SH 20 McNary
~======:t= I H -10
I__ E I Paso ____. jTest Road
Figure 10. El Paso Test Road Location
32
43+55.51
113
173
238 243
448
+55
+55
+55 +55
+55
518 +55
CD
-®
~
@
-Control ~
·~
-I
®
~
EB IH-10
~
t WB
IH-10
®
-@
L
®
® I
-
®
. Figure II. El Paso Test Sections
33
43 + 55.51
101 +76
162
226
386
459
+00
+76 N--+
+60
+72
528 +36.74
approximately 25 percent of this value with five axle semi-trucks
accounting for approximately 60 percent of all trucks.
Subgrade soils on the E:l Paso Test Road are poorly qraded sands and
gravels, some containing plastic fines, classified by the Unified .Soil
Classification System as GP-C-C and SP-SC for gravels and sands,
respectively.
Buffalo Test Road --------------~
Buffalo Test Road State proiect designation is FRI-45-2(68)180
located on Interstate Highway 45 (IH-:45) in Freestone County, from the
Leon county line to us 84 as shown in Piqure 12. Test sections are each
approximately 0.80 mile in length in the northbound travel lane as shown
in Figure 13.
'Ihe Buffalo Test Road is constructed on R inches of continuously
reinforced concrete pavement over 4 inches of asphalt treated basecourse
and 6 inches lime treated subqrade. The original pavement structure was
constructed in 1q71.
Distress consisted of typical hairline random transverse cracks at 3
to 6 foot intervals, and infrequent punchouts.
Traffic on the Buffalo Test Road was measured by Texas SDHPT in 1983
at approximately 15,000 ADT. 'Ihe total volume of trucks is approximately
20 percent, Volume by individual truck type has not been measured in
this area and is therefore, not available.
Subqrade soil types along the Buffalo Test Road alignment were
obtained from recently recorded Soil Conservation Service loqs (23).
Classification of subqrade soils by the Unified system are as. low
plasticity clays and silty clays, ML-CL, along much of the alignment with
some clays borderinq on high plasticity.
Brownsville Test Road State project designation :i.s MW 017(2) located
on State Highway (SH4) in Cameron County from the International Rridqe
34
US84
us 79
N
f IH-45
i ., 0 0
0::: -en {!!. 0 0 .... .... ::t m
Fairfield
_l _ _!"r~stone~Co.:,. _
Leon Co.
Buffalo
Figure 12. Buffalo Test Rood Location
35
704+50
657+50
610 +50
595+30
587+80
TNo Tests
- 220+00
212 +50
205+00
188+30
168+00
-
-
--
--
-
-
.A
"'
<V
I
®
® @
.. ~
1".
® ®
I CD
J y
~egin Project IH-45 NB
N
t
Leon- Freestone County Line Station 0+ 00
End Project IH-45 NB Station 905i"50
@
® I
(@
I ®
®
v
878+ 50
832 +50
786 +50
745+50
704 +50
Note : Station in feet
Figure 13. Buffalo Test Sections
36
north approximately two miles. Test sections are located in travel and
passing lanes both north·and southbound as shown in Fiqure 14.
The existing pavement structure prior to rehabilitation consisted of
appro:>cimately 4 inches of asphalt concrete placed over 8 inches of
crushed stone base over 8 inches of soils of ADT river sand.
Traffic on the Brownsville Test Road was measured in 1983 by Texas
SDHPI' at approximately 23,000 ADT.
Subgrade soil types along the Test Road alignment are clarrified as
CL and ML from Station 15 + 00 to approximately 55 too. Soils becane
more plastic to the north, cla5sified as CH and MH from Station 75 + 00
to 110 + 00.
37
t-4
::l rt OJ ro ro -s c.o ::::J .....
(./')QI::::J :I: rt ..... -o .p.o-s
::::J 0 Q.l c..... ..... (1)
w (X)
n co rt -s ..... 0.
c.o (1)
('.)
u + 0 0
N U1 + 0 0
v) C)
+ 0 0
w Ul + 0 0
.p. 0 + 0 0
.p. U'l + 0 0
U'l 0 + 0 0
,_ ___ '···-~-~-·-- ··-·. - ·r ---- -· -~ - . --- --,-· -· --- - -------,------------r----....... -
~ ~
U'l 0 + 0 0
.,..._ _________ ·-- - Section 8 - -- .. --
r Section _ ... . Section_ . 1------···--l---±-... ----.1 ·-
~---~---------- --- _______ t 1 18 17
-------- ---- -- -r U'l N ON
+ Ul N 0""'-J
+ --r- --· ---.---- ----····'
Section 9 --···.-···--·-· -· I ---· - -- ~--i
S_ection 1 -
VlW ON
+
t t- -- ----------··
Section 16 --~~~=-_ ___.
. -- Section 7 -
·- --- -----· ______ l --------
.NB _....
--,----Section 10 t- ·---Section 2 -----··
----- ----f- --~----·· --'------'---------1-
! - ·----- ----t- ---·
-- --- ---· Section 6 _ __.:__ -· - ------+- - -t---- -- -
-- Section 5 ,..._ SB
__ --_____ ·__ _ --: ~-ect ion _1: •----~- --- ---- ----·Section 14 ·---~
. - l-- -·. ···'- -------U'l ........ U'1 00 0....._. ON
+ +
I --, -- . J . Section ection - -· · · Sect10n 11 -- - - +
- ·--·-f-----~-- .- +---·-- • .- ·--·-- . -f· __ _± 12 - 13 O 1
------- Section 3 - · - · - Section 4 -- ------'-------- -· ---- ----- -- -··- ----~
0)
0 + 0 0
0" .p. + 0 0
0" \0 + 0 0
........ U'1 + 0 0
(X) 0 + 0 0
ex: U'1 + 0 ·o
NB ~
\0
<.?· 0 0
Figure 14. Brownsville Test Road -Test Section Locations
CHAPI'ER V
TEST IDAD OONS'IRUCTION
El Paso-Preconstruction
Prior to construction three segments of pavement each 500 feet in
length.were located within each test section. 'Ihese sections were
surveyed by photographing the 12 foot wide and 500 foot long pavement
section prior to rehabilitation. The locations of these photolog
segments within each test section are as shown in Table 7.
Photolog equipment consisted of a test vehicle equipped with a
motorized 35 mn camera rrounted in front of the vehicle in a vertical
position over the pavement. '!he camera and vehicle speed were
synchronized such that each photographic frame recorded pavement
measuring 8 by 12 feet with a six ·inch overlap for adjacent segments.
All photgraphs are on file at Texas Transportation Institute, College
Station, Texas. Each photograph of the test sections was studied to
determine the extent of distress present prior to construction. Distress
types and levels of severity were recorded for each test section
following the criteria described by Epps, et al. (13). Results of the
photolog s1l1llllary appear in Appendix A.· An index of pavement condition
has been described (14) which quantifies all forms and levels of pavement
distress. Based on·rnaintenance costs, this index, or Pavement Rating
Score (PRS), allows numerical comparison of pavement condition. A PRS
value of 100 describes a pavement with no distress. Progressively lower
~s values describe pavement condition with more severe forms of
distress. 'Ihe form shown in Figure 15 is used to catalog distress
observed on the pavement. Deduct values are assigned to each type and
level of distress according to Table 8. 'Ihe sum of deduct values is
subtracted from 100 resulting in the pavement ratio score (PRS).
The results of this analysis for the ten El Paso test sections appear
in Table 9.
39
·Table 7. El Paso Photolog Locations ..
Test Station Section Photo log From To
1 1 68+65.5 73+65.5 2 86+00 91+00 3 104+00 109+00
2 4 136+00 141+00 5 145+00 150+00 6 150+00 155+00
3 7 180+00 185+00 8 186+00 191+00 9 . 191+00 196+00
4 10 485+00 490+00 11 490+00 495+00 12 520+00 525+00
5 13 510+00 505+00 14 490+00 495+00 15 480+00 4i5+00
6 16 460+00 455+00 17 455+00 450+00 18 450+00 445+00
7 19 180+00 175+00 20 175+00 170+00 21 170+00 165+00
8 22 120+00 115+00 23 115+00 110+00 24 110+00 105+00
9 25 95+00 90+00 26 80+00 75+00 27 75+00 70+00
Control 28 238+55 243+55
40
~ 1-- FOREMAN NO. ::u c )> u; ~ ~ 1-- ...,__ HIGHWAY CLASS ,
:0 ::u
, ~ c .,
~ ...,__ (/) n - ~ COUNTY NO. ~ ~ - ~
0 ~ - z z ~ -- I-- ~ ~ 0 - 1-- X -- I-- HIGHWAY NO. B
~ -1--~ ~ ~
1--~ I 1- ~
B 0 c ~ 1-~ 1-- n ~ 1- ~
1--1-- CONTROL ~ B 1- 1-
~ 1-- 0 ~ ~
z ~ ~
1--1-- SECTION ~ 1-ft) -< ~ ~
__. (J'l . "t) Q < ft)
1-- ...,__ .,. , ~ 1-
~ 1-- :a )> ~ ~
0 :0 ~ I- c
~ ~ 1-- ~
1--- i-- - ~ ·~o-- I-- ... - 1-
1--~ 0 ~ 1-1- 1-
+="' 3 ...... ft)
~ -LA~E .... ,__
(!)SLIGHT (2) MODERATE (3) SEVERE PUMPING 3)1- !5 (Z) 6-10 ®>10 FAILURES/MILE
::0 Q -
SLIGHT It!>~ -6 )loo SURFACE MODERATE " CJI - ~~ DETERIORAT~ Ul u. ' SEVERE 0 0 Ui )I> ,.
~ ~ , 0 ., 3 ell
SLIGHT 10 fl' e ~Hs .o MODERATE " CJI - ~zoe SPALL lNG ~~
Ul ' ' r SEVERE 0 Ul - ~-t ,..
0 Ul en en •z SLIGHT :~ ~~ r ~0 (1),.- LONGITUDINAL MODERATE ... "'~ en
N -o • CRACKING "'"' 8 :8? ~ ~::0 "'I zE SEVERE :-t -tf'l GOOD 18 e e )loo cnz
-t FAIR " CJI - ~~ PATCHING (") - ' I
POOR CJI Ui Ul )I> 0 z
MODERATE ~y <n,.z (")
~"'o FAULTING ::0 SEVERE !"'::U. "' CLOSED (j) !5-10 (") ...
CRACK ::u"' OPEN [2) OTHER SPACING n,. ,.. MODERATE Dl-10 %INTERSECT o<
Zf'l SEVERE 12> >10 lNG CRACKS ~~c
(D I 201 "' SAWED JOINT ez
CONSTR. C21 ,.20' SPACING zU: SLIGHT 8 e e ,. -t
MODERATE y Ul -)I>,. z TRANSVERSE ~
- t I ~~~ CRACKING o SEVERE 0 IQ • r z -'OINT a CRACK ffiSeoled C lPortiollr G) No Seal 0(
~ FOREMAN NO.
~ HIGHWAY CLASS
~COUNTY NO.
~ HIGHWAY NO.
rn CONTROL
1--+-1 SECTION
ffii rn~
LANE
,-0 n. !t 0 z
1: 0 z ~ %
B 0
~
B -< "' )> :u
~
::a )II> ~
"' :::a (/)
sLIGHT s 8 e I • MODERATE ;!. _' "; i:c.t I RUTTING SEVERE 0 Jl ~ •
2 (/) ...... :u n -t z 0
E3
SLIGHT 9 e e I ,. ~~-~~~~TE ! ; ~ eae IRAVELING ~ SLIGHT 9 A 6 ,. MODERATE :. ' "i i:at FLUSHING SEVERE 0 "" ~ ll>
SLIGHT 9 @ S ,. MODERATE Z. ~ 7 ~at SEVERE o -~ Ui ,.
SLIGHT 9 @r el ~ I ALLIGATOR ~ MODERATE :_ ~ 7 :at CRACKING ~ SEVERE Ul Ul Ul
.:S.:.L.:.:IG:,:;H~T~=-18 --se-1 ~,. !:ILONGI~~-DI~A~~ v -- Jl'f'IZ MODERATE N ; 8 9 j:ao :a .,_ CRACKING
- 8 • I I z -t --
9 e-e I en ,. zl TRANSVERSE ·~ ..;.._---~~ _! ~ 7 ; ~ 0 CRACKING -t ..;;;;..;;....;...;~--· 0 ••
CRACKS (I) Sealed (2)Portially Sealed (3)Not Sealed
GOOD 19 6 61,. FAIR !. ~ 7 ~at !PATCHING ---- • ~ Ul ,.
Table 8. Pavement Rating Deduct Values.
Type of Distress Degree of Distress Extent of Distress * ( 1 ) (2) . (3)
Rutting Slight 0 2 5 Moderate 5 7 10 Severe 10 12 15
Raveling Slight 5 8 10 Moderate 10 12 15 Severe 15 18 20
Flushing Slight 5 8 10 Moderate 10 12 15 Severe 15 18 20
Corrugations Slight 5 8 10 Moderate 10 12 15
Severe 15 18 20
Alligator Cracking Slight 5 10 15 Moderate 10 15 20 Severe 15 20 25
Patching Good 0 2 5 Fair 5 7 10 Poor 7 15 20
Deduct Points for Cracking
Longitudinal Cracking ·
Sealed Partially Sealed Not Sealed * ( 1) (2) (3) (1) (2) (3) ( 1 ) (2) (3)
Slight 2 5 8 3 7 12 5 10 15 Moderate 5 8 10 7 12 15 10 15 20 Severe 8 10 15 12 15 20 15 20 25
Transverse Cracking
Slight 2 5 8 3 7 10 3 7 12 Moderate 5 8 10 7 10 15 7 12 15 Severe 8 10 15 10 15 20 12 15 20
* Numbers in parentheses refer to quantity of distress observed as indicated on Figure 1.
42
Table 9. E1 Paso Preconstruction Pavement Rating Scores.
Test Photo1og Cracking PRS Overall PRS Section Trans. Long. Allig.
1 1 7 63 65 -1 2 70 88 70 23 3 63 93 85 36
2· 4 60 65 85 8 5 75 93 85 48 6 95 93 95 78
3 7 78 88 80 29 8 73 88 80 26 9 75 93 95 56
4 10 63 70 60 -39 11 83 98 100 81 12 63 70 70 -17
5 13 75 80 60 3 14 90 78 65 28 15 87 88 80 43
6 16 83 88 65 12 17 83 93 80 48 18 83 88 80 38
7 19 78 78 85 16 20 90 88 95 63 21 90 93 90 61
8 22 90 93 95 68 23 78 93 . 95 56 24 90 93 90. 63
9 25 75 88 85 43 26 90 70 80 28 27 68 88 80 19
10 28 95 98 98 86
43
Table 9 contains the PRS ~alues obtained by measuring al~ combined
forms of distress present in each test section. PRS values are atso
shown which were obtained by measurinq individual types of cracking •
. These cracking PRS ratings are presented such that a more precise
comparison may be made between test sections for crack related distress.
The asphalt-rubber interlayer is intended to reduce the rate at which
cracks in the underlying pavement propagate the new asphalt concrete
overlay. 'Ihe "cracking PRS" values, therefore, will provide a basis for
which future condition surveys can be compared. By comparing PRR values
for transverse, longitudiual and alligator cracks, a measure-of
interlayer perfonnance within and between test sections can be obtained
based on percent original PRS.
El Paso-Construction ~._~--~~u-._-~
Asphalt-nibber interlayers were placed on June 23, 24 and 27, 1983 by
International Surfacing, Inc., Phoenix, Arizona. Sections 5 to 9 were
placed June 23, 1983, followed by sections 1 to 3 on June 24, 1983.
Section 4 was placed June 27, 1983. Environmental conditions during
construction were favorable with early morning temperatures of
approximately 70F and afternoon temperatures of lOOF.
Observations and tests made during construction included the following:
I. Asphalt-rubber mixing
A. Assuring desired rubber types were used in
asphalt-rubber to be placed over selected test section
locations.
B. Proportion of asphalt and rubber.
c. Blending time.
D. Blending temperature.
E. Viscosity prior to application.
F. Sampling of asphalt and rubber.
II. Asphalt-rubber application.
A. Asphalt-rubber spray rate.
44
B. Aggregate spread rate.
c. Asphalt-rubber coolinq rate.
D. Sampling of asphalt-rubber.
Considerable coordination was necessary during construction to assure
that the desired asphalt-rubber combinations and application rates~ as
shown in Figure 4, were placed over photolog locations appearing in Table
7. This required adjusting distributor volumes such that materials could
be placed contiquously.with minnnum disruption to construction
procedures.
Asphalt arrived at the mixing site by highway transport where it was
pumped into a storage container. Granulated rubber was shipped from the
three manufacturers in 50 or 60 pound baqs.
Blending of the asphalt and rubber required two pieces of equipment.
Initial mixing of asphalt and rubber occurred in a pre-blending device
which combines asphalt and rubber in the approx~te pre-blend
proJ;X>rtions desired. After the asphalt and rubber are pre-blended, the
material is pumped to the asphalt distributor. The flow of blended
asphalt and rubber are continuous from pre-blender to distributor in the
approxnnate proportions desired. Final proportioning is accomplished
after all of the rubber is in the distributor by adding additional
asphalt.
A sample· calculation follows which describes how the n~r of baqs
of rubber and gallons of asphalt cement are determined to achieve a blend
containing 22 percent rubber by weight of blend.
Assumption:
Distributor volume
Rubber Rag weight
Unit Weight Asphalt Cement
~ 350F
Unit Weight Asphalt-Rubber
@ 350F·
45
4500 qallons
SO pounds
7.54 pounds/gallon
7.54.pounds/gallon
Find: Number of bags of rubber and gallons of ·asphalt ce100nt to
yield a 4500 gallon asphalt-rubber blend at 22% rubber by weight of
blend.
Rubber:
Asphalt Cement:
4500 ix 7t54 Jx .2] = 149.3 baqs 50
4500 . X 7,54 X . , 7A = 3510 gallons Hd7.54
Specific gravity of asphalt-rubber was measured at various
temperatures in the laboratory following procedures described bv ASTM D70
(25). Weight to volume conversions were done with a hiqh boiling point
oil such that specific gravity could be measured above 212F. The graph
shown in Figure 16 of asphalt-rubber specific gravity was used in the
calculation above for the required volune to Y~eight conversion. J\bte the
difference in asphalt-rubber specific gravity as measured and that
calculated from cubical coefficient of expansion data. A 95 percent
confidence limit ~n measured values encanpasses calculated va~ues. '!his
seems to indicate volume change in asphalt-rubber is due to conblned
thennal expansion of the constituents. The larqe variation in specific
gravity results shown in Figure 16 indicates this test is probably of
lnmited use for quality control unless more precise results can be
achieved.
Results of observations and tests performed during mixing of the
asphalt-rubber appear in Table 10. Note that the field viscosity of the
asphalt-rubber blend appears to depend on rubber content as shown in
Table 10 and plotted in Fiqure 17. Note that the type of rubber affects
the viscosity of the blend as shown in Figure 17. Viscosity tests were
performed usinq a portable Haake rotational viscometer on samples of
asphalt-rubber obtained directly from the distributor truck approxnnately
50 minutes after all rubber had been added to the truck.
46
LIO A5phalt- Rubber : Type A 24 percent by weight
Calculated
1.05 s.,. >- ,0. .. ,..~
> .,, 0 u ·~
. :D.o C.!)
.,.. c
1.00 o,, .
u . I~ .I} -..... ~.
u 1..,., . cu ,, Q.
'(/)
Measured
.95 (ASTM 070)
.90
0 100 200 300 400
Temperature, F
Figure 16. Asphalt- Rubber Specific Gravity
47
Table 10. El Paso Mixing Observations and Test Results.
Test Beginning Time Req'd to Time Between Temp, F Viscosity Rubber Rubber Section Date Time Fill Truck w/ Full Truck & Prior Prior to Type Content,
of Blend, min. Application, to App- Application, Percent Day min. 1 i cation. poises
1 6/24/83 4:35am 40 105 320 20 A 24
2 6/24/83 5:20am 40 95 390 9 c 22
3 6/24/83 6:02am 53 90 320 35 B 26
4 6/27/83 11:40am 35 110 338 18 B 22 ..t::'-00 5 6/23/83 5:25am 55 85 340 15 A. 22
6 6/23/83 6:.25am 55 90 330 15 c 26
7 6/23/83 11:20am 30 160 345 10 c 24
. 8 6/23/83 1:15pm 30 135 325 23 A 26
9 6/23/83 1:50pm 30 125 330 25 B 24
rn <U rn
cf ~ -en 0 u en >
-o- RUBBER A
40 -a- RUBBER B ......(),- RUBBER C
30
20 338F
340F
10 390F 345F
22 24 26
Rubber Content , Percent
*TEMPERATURES SHOWN ARE VALUES CORRESPONDING TO VISCOSITY MEASUREMENTS
Figure 17. El Paso Asphalt -Rubber Viscosity
49
Rubber type C in addition to generating the lowest asphalt-rubber
viscosity.relationship; also caused a considerable volume increase in the
blend as mixing progressed. This was manifested in overflows ·of asphalt~
rubber fran the top batch of the 4500 gallon distributor 'truck for test
section nd.xes 6 and 7. The overflows occurred during routine pumping
of the blend after approximately 2300 gallonS had been loaded. Overflow
was avoided for the third blend containing Rubber C by loading the first
half of the blend at a slower rate. Moisture . contained in the rubber
is thought to be the cause of this adverse reaction and may be. related
to the cryogenic processing technique.
Asphalt-rubber temperature measurements were obtained :to detennine
the rate at which the binder loses heat prior to aggregate application.
Temperatures were measured using a Fluke digital thennaneter under
varying ambient temperature conditions. 'Ihese data are plotted on
Figure 18 with calculated theoretical values ( 15) .
Temperature loss in the asphalt-rubber binder is rapid as shown by
Figure 18. Binder temperature decreases to near the initial paverre1t
temperature in approximately 90 seconds under the conditions of the test.
Verification of binder aggregate application quantities ~
accanplished by Texas SDHPT persormel. During construction, measurem;mt
of the applicati~ quantitywas·accanplished at approximately 1000 to
3500 foot intervals until the proper application rate was achieved.
Measurement of application rate was accomplished using· calibrated
metering rods accanpanying each distributor truck. Measurement of
aggregate spread quantity was accanplished at similar intervals by volune
of aggregate. Rates of binder and aggregate within each test section
are shown in Table 11.
Research binders as shown in Figure 4 were applied over photologs
in appropriate test sections at the rates shown in Table 11. However,
the distributor truck emptied its contents before reaching photolog 12 in
50
Figure 18. El Paso Asphalt -Rubber Temperature Loss After Application
51
Table 11. El Paso Application Quantities.
Test Photo log Measured Desired. Section Asphalt- Asphalt-
Rubber Rate, Rubber Rate, gsy gsy
1 1 0.36 0.40 2 0.41 3 0.41
2 4 0.35 0.35 5 0.38 6 0.38
3 7 0.45 . 0.45 8 0.45 9 0.45
4 10 0.38 0.40 11 0.38 12 *
5 13 0.44 0.45 14 0.44 15 0.44
6 16 0.41 0.40 17 0.41 18 0.41
7 19 0.44 0.45 20 0.44 21 0.44
8 22 0.36 0.35 23 0.36 24 0.36
9 25 0.36 0.35 26 0. 36 27 0.35
Control 28 N/A N/A
* Dis-tributor truck emptied contents before reaching photolog No. 12.
Note: Aggregate spread quantities were uniform throughout project ranging from 116 sq.yd./cu.yd. to 117 sq.yd./cu.yd. (19.5 to 19.7 lb./sq.yd.).
52
Test Section 4 and therefore, no research binder is present over photol0q
12.
Placement of overlay asphalt concrete began July 18, 1983,
approx~tely four weeks after asphalt-rubber application. Core
spec~ns were obtained from each test section to detennine overlay
thickness and provide samples for evaluation of physical properties as
reported in Tables 6 and Figure 3. Results of thickness measurements are
shown in Table 12.
T~ations of test sections were preserved after construction for
future reference. Monuments consistinq of 4 inch by 4 inch by 8 feet
cedar posts were located at the beginning of each test section along the
highway right-of-way. R:>sts were painted white and contain black
lettering denoting stationing shown on Figure 11 of specific locations of
test section boundaries. Location of photologs within test sections for
future condition surveys will be sTimplified by reference to these
monuments.
Buffalo-Preconstruction
Eight sections of pavement each approximately 0.80 lane mile in
length were selected to receive the various asphalt-rubber hlends
shown in Figure 7. Four additional pavement sections, each 750 feet in
length, were selected as control sections. 'Ihree segments of pavement
each 500 feet in length were selected in each of the eight test sections
for photolog surveys as previously described for El Paso Test Road. The
entire length of the control sections were photoloaqed. Incations of
_photologs are as shown on Table 13. Photo log equipnent was as used on
the El Paso Test Road.
Condition: surveys on site were combined with cracking data obtained
f~ photologs to provide _FRS values for test and control sections.
Table 14 contains PRS values obtained after completing the condition
survey and photolog interpretation. All photographs obtained dur:i.nq
53
Table 12. El Paso Overlay Thicknesses.
Test Photo log Overlay Section Thickness, in.
1 1 1.75 2 1. 25 3 1.25
2 4 1.25 5 1.25 6 1.25
3 7 1.50 8 1.50 9 1. 25
4 10 1.75 11 2.25 12 *
5 13 1. 75 14 2.75 15 2.00
6 16 1.25 17 ·1.25 18 1.00
7 19 1. 75 20 1.50 21 1. 25
8 22 1.50 23 1.50 24 1. 50
9 25 lo50 26 1.50 27 1. 25
Control 28 1.50
* Photo logged, but no research binder in this area.
54
Table 13. Buffalo Photolog Locations.
Test Photo log Station Section From To
1 1 to 3 188+30 201+24
2 4 to 5 205+00 212+50
3 6 to 7 212+50 220+00
4 8 to 9 587+80 595+30
5 10 to 11 595+30 604+40
6 12 to 14 631+20 645+50
7 15 to 17 683+00 698+50
8 18 to 20 714+15 729+50
9 21 to 23 755+60 770+70
10 24 to 26 810+00 825+00
11 27 to 29 860+00 875+00
12 30 to 32 889+00 904+00
55
Table 14. Buffalo Preconstruction Pavement Rating Scores.
Photo log
1 2 3
10 11 12 13 14
. 21 22 23 24 25 26 27 28 29 30 31 32
PRS
90 90 90
. 90
100 100 100 90
. 90
100 90
100 90 90 90
100 100 100 90
100
Note: Much of the distress on Buffalo Test Road consisted of random transverse cracks at less than 5 foot intervals. In most cases cracks were closed and not 11working 11 ·significantly. ·This results in a deduct score of 10. Deduct scores nf 0 resulted from closed cracks occurring at between 5 and 10 intervals.
56
surveys are on file at Texas Transportation Institute, College Station,
Texas.
Buffalo-Qpp?tructjon
Asphalt-rubber was placed over test sections August 20, 21 and 22,
1984 by Arizona Refining Company, Phoenix, Arizona. Environmental
conditions during construction were favorable with early morning
temperatures of approxnnately 70F and afternoon temperatures approaching
lOOF.
Observations and tests made during construction were identical to
those for the El Paso Test Road. Similar coordination was required of
contracting efforts such that asphalt-rubber canbinations desired as
shown in Figure 7 were placed in appropriate locations over photoloqs as
shown in Table 13. Distributor volLUnes were adiusted as for El Paso such
that the desired asphalt-rubber mixes were placed at appropriate
locations on test sections.
Blending of asphalt and Sundex 790 at 6 percent Sundex by blend
volume was accomplished prior to blendinq with rubber. Pre-blending of
asphalt-rubber was accomplished as on the El Paso proiect prior to
pumpirig the blend into.distributor trucks. Here the asphalt-rubber blend
remained in the trucks for the desired digestion period prior to
application~
Digestion was varied as a control variable in this experiment as
explai.ned previously for laboratory prepared mixes. 'IWo levels of
digestion were achieved. 11 I.oW11 digestion describes blends of 2 to 2 3/4
hours. 11Hiqh 11 digestion describes blends of 16 to 16 1/2 hours.
Rubber concentrations of lR and 22 percent by weight of the blend
were used.
Results of observations and tests performed durinq mixing of the
asphalt-rubber appear in Table 15. Viscosity and rubber content appear
to be directly proportional as occurred for El Paso blends. However,
57
Table 15. Buffalo Mixing Observations and Test Results.
Test Beginning Time Req'd to Time Between Temp, F Viscosity Rubber Rubber Section Date Time Fill Truck w/ Full ·Truck & Prior Prior to Type Content,
of Blend, min. Application, to App- Application , Percent Day hrs-min. lication poises
1 8/22/84 5:30pm 50 15-40 390 11 A 18
6 "8/21/84 7:05am 35 2-55 -390 48 A 22 1,.11
7 8/20/84 7:07pm 45 15-53 400 21 A 22 (X)
8 8/20/84 8:21pm 40 15-14 400 7 A 18
9 8/20/84 11:45am 45 2-5 400 14 A 18
10 8/21/84 1:00pm 105 2-5 400 45 A 22
11 8/~1/~4· :45pm 35 2-10 402 13 A 18
12 8/21/84 6:30pm 40 15-50 390 19 A 22
viscosity appears to be inversely proportional to digestion period. 'The
results of these tests are plotted in Figure 19.
Temperature loss of the asphalt-rubber was measured as for the Bl
Paso Test Road. Results of these tests are shown on Figure 20. Results
are s~ilar to those observed at El Paso. Texas SDHPT personnel verified
binder and aggregate quantities as part of routine quality control
procedures. However, unlike El Paso, binder quantities were determined
by weight rather than voh.nne. Each asphalt-rubber distributor was
weighed prior to, and after application. The difference in weight was
converted to volume and the corresponding application rate determined for
the measured pavement area covered. 'Iherefore, application rates shown
in Table 16 reflect averages throughout each test section.
Buffalo overlay asphalt concrete consists of a ~xas Type C leveling
course and a one-inch Texas Type D surface course. Placement of the
levelling course beqan September 10, 1984 and was completed November 16,
1984. Each test section was sampled by coring to obtain laboratory
specimens and to verify overlay thickness. Physical properties of the
asphalt concrete are reported in Table 6 and Figure 3. Results of
thickness measurements of core samples are shown in Table 17.
Locations of photologs within test sections are permanently marked
using raised reflective pavement buttons positioned on the right shoulder
of the northbound lane. Precise location of photologs for future
condition surveys is therefore possible .by reference to these pavement
markers.
TWelve pavement sections were selected to receive asphalt-rubber and
various canbinations of a.gqregates. 'Ihe asphalt-rubber binder
formulation was held constant for this exper~nt. Rubber was blended at
60 percent Type n and 40 percent 'I\fpe E as described in Tables 2 and 4.
Six additional sections were selected as controls. Control sections
consisted of: 1) no treatment, 2) asphalt cement interlayer, 3)
59
50 IJ. 390F
400F
40
~ en ·~ Cl)
30 ;;
en " ·~ 0 Q a. .. .. 0 >. . """' ... en 0 c 400F u 20 en
> ~,o<' 390F
·~·" 400F
Q\: ~,~~
402F
10 390F
400F c
18 22
Rubber Content, Percent
Figure 19. Buffalo Asphalt-Rubber Viscosity
60
.. CLJ ... :;) -
400
300
~ 200 Q.
E· CLJ .....
100
Sect ion Temperature, F Bose Ambient
8 140 95
10 135 92
0 ~--------------~----------------~---------------0 1.0 2.0
Time, Minutes
Figure 20. Buffalo Asphalt- Rubber Temperature Loss After Application
61
3.0
Table 16. Buffalo Application Quantities.
Test Section Binder Rate, gsy Aggregate Rate, sy/cy
1. 0.58 95
2 0.57 90
3 No Binder No Aggregate
4 No Binder No .Aggregate
5 o.ss 80
6 0 .• 57 77
7 0.56 . 79
8 0.57 77
9 0.52 75
10 0.59 80
11 0.54 78
12 0.56 79
62
Table 17. Buffalo OVerlay Thickness.*
-Test· Photo log overlay Section Thickness, in
.............................. 1 1 2.4
2 2.5 3 2.3
2 4 2.5 5 2.6
3 6 2.6 7 3.3
4 8 3.5 9 3.8
5 10 3.8 11 3.8
6 12 3.8 13 3.5 14 3.3
7 15 3.4 16 3.5 17 3~5
8 18 3.3 19 3.3 20 3.1
9 21 3.A 22 3.5 23 3.8
10 24 3.4 25 3.4 26 3.A
11 27 3.0 28 3.1 29 3.1
12 30 4.0 31 4.0 32 4.0
*Thickness after construction in 19A4. A 1" surface course was applied over entire pavement in 1985.
63
. ...
polymer asphalt interlayer. All sections were replicated to provide a
statistical bsis for later analysis of performance betwen section~. A
description of all materials used is shown in Table 18.
~ 500 foot photolog was recorded in each test section. Locations of
photo logs are as shown in Table 19. Photo log equipnent and technique was·
used at Buffalo and El Paso.
Condition surveys on site were combined with crackinq data from
photologs to provide PRS values. Table 20 contains these PRS data.
Brownsville - Construction ..............,.. .. ............. •• , ! .... ...
Asphalt-rubber was first placed over non-experimental pavement
sections such that binder shot rate and aggregate spread rates could be
adiusted. After calibration was completed, test section construction
began. Asphalt-rubber was placed on all test sections by October 12,
1984 by Arizona Refining Company, Phoenix, Arizona. Control s~ctions
were placed by SDHPT personnel by October 26, 1984.
Observations and tests made during construction were identical to
those for the El Paso and Ruffalo Test Roads. Similar·coordination was
required of contracting efforts such that asphalt-rubber seal coat
combinations desired were placed in appropriate locations over photologs.
Blending of asphalt and Sundex 790 at 6%·sundex by blend volume was
accomplished prior to blending with rubber. Pre-blending of
asphalt-rubber was accomplished as on the El Paso and Buffalo projects
prior to pumping the blend into distributor trucks. Here the
asphalt-rubber blend remained in the trucks durinq digestion prior to
application.
nigestion remained constant in this exper~nt. Rubber and asphalt
were blended for approxnnately 1 hour after all rubber was added to the
blend for each test section.
Rubber concentration remained constant at 18 percent by weight of the
asphalt-rubber blend. Texas SDHPT personnel verified binder and
64
Table lA. Brownsville Test Section Materials
Test .Aggregate Aggreqate Size Overlay Section Binder ~cation Boti;~mlis>.P 'Ih ickn~~ .. §.e. in -··- ---- .............. -··-
1 A-R tX>uble C,rade 3/Grade 3 N/A
2 A-R Single Grade 3 N/A
3 A~R Ibuble C,rade 3/Grade 4 N/A
4 AC Double Grade 3/Grade 4 N/A
5 A-R 1buble Grade 3/Grade 3 1.4
6 A-R Single Grade 3 1.2
7 A-R 1buble Grade 3/Grade 4 1.1
8 AC 1buble Grade 3/Grade 4 1.3
9. A-R 1buble Grade 4/Grade 4 · 1.3
10 A-R 'Single Grade 4 1.0
11 A-R Single Grade 4 ·rwo deep 1.1
12 None None N/A 1.2
13 R:>lymer Double Grade 4/Grade 4 1.o
14 A-R IX>uble Grade 4/Grane 4 N/A
15 A-R Single Grade 4 N/A
16 A-R Ringle Grade 4 Two deep N/A
i7 None None N/A N/A
18 R:>lymer Double Grade 4/Grade 4 N/A
65
Table 19. Brownsville Photolog Locations
Test §2£tion(.!'l)g~C}.l9il Location ........ _._
1 25+00 to 30+00
2 40+00 to 45+00
3 64+00 to 69+00
4 80+00 to 85+00
5 85+00 to 80+00
6 69+00 to 64+00
7 45+00 to 40+00
8 30+00 to 25+00
9 25+00 to 30+00
10 40+00 to 45+00
11 64+00 to 69+00
12 77+50 to A2+50
13 82+50 to 87+50
14 85+00 to 80+00
15 69+00 to 64+00
16 45+00 to 40+00
17 32+50 to 27+50
18 27+50 to 22+50
Note: Stations are south to north.
66
Table 20. Brownsville Preconstruction Pavement Ratinq Scores.
---------rl·-··-··-.. -·-u-rl•-·rl-·------·-··-·-·--c~·~acking PRS----·-·-·-·-.. --ov __ e-ra-·l~i~-·--
Test Section ----- -· Tran~y. I.Qng. ..E 1 iq:--. ---·-· _rl ~rru-.. .. s ..... __
1 95 95 85 75
2 97 95 95 87
3 97 95 95 87
4 97 95 100 92
5 93 95 95 83
6 97 95 95 87
7 95 93 95 83
8 98 98 85 81
9 97 95 100 92
10 95 95 100 90
11 97 95 100 92
12 97 95 100 92
13 97 95 100 92
14 97 95 100 92
15 100 95 100
16. 97 100 100 97
17 97 95 100 92
18 97 95 100 92
67
aggregate quantities as part of routine quality control procedures. At
the beginning of the project,. binder quantities were intended to be
detennined by volume. However, the trucks supplied by the asphalt-rubber
contractor had not been calibrated, and some difficulty was experienced
while attempting calibration on the ioh site. Therefore, shot rates were
determined by weioht. Each asphalt-rubber distribtitor was weighed prior
to, and after application. '!he difference in weight was converted to
volume and the corresponding application rate determined for the measured
pavement area covered. Therefore, application rates shown in Table 21
reflect averages throughout each test section.
Brownsville overlay asphalt concrete consists of approximately 1 1/4
inches Texas TYPe D asphalt concrete. Placement of the 1 1/4 inches
Texas Type D asphalt concrete. Placement of the overlay began after
asphalt-rubber and control section seal coats had been in service at
least one week. Each test section was core drilled to obtain laboratory
specimens and to verify overlay thickness. Physical properties of the
asphalt concrete are reported in Table 6 and Figure 3. Results of
thickness measurements of core samples are shown in Table 22.
Locations of photologs are permanently marked using raised reflective
pavement buttons position on the right shoulder. Precise location of
photologs for future condition surveys is therefore possible by reference
to these pavement markers.
68
Table 21. Brownsville Test Road Aggregate and Binder Application Rates.
Test Design Measured Design Measured Measured Section Aggregate Aggregate Binder Binder Embedment Comments
Rate, sy/cy Rate, sy/cy Rate, gsy Rate, gsy Depth, %
1 80/80 56/56 0.71/0.69 0.77/0.85 38/40 Severe Flushing
2 80 56 0.69 0.78 Severe Flushing
3 115/80 83/56 0.53/0.69 0.48/0.71 -/52 Slight Flushing
4 115/80 56 0.27/0.36 0.60 Severe Flushing
5 80/80 56/56 0.71/0.69 0.67/0.65 14/43 No Distress
6 80 56 0.69 0.76 48 Slight
7 115/80 80/56 0.58/d.69 Flushing
0.59/0.71 26/48 Severe Flushing
8 115/80 80/56 0.27/0.36 0.45/0.58 Severe Flushing
9 115/115 83/83 0.53/0.69 0.49/0.51 -/51 Severe Flushing
10 115 83 0.51 0.58 50 Severe Flushing
11 57 80 0.51 0.65 70 Severe Flushing
12 None None None None
13 115/115 83 * 0.27/0.25 0.48 * Severe Flushing
14 115/115 83/80 0.53/0.51 0.56/0.52 24/47 Slight Flushing
15 115 83 0.51 0.56 53 Severe Flushing
16 57 80 0.51 0.66 50 No Distress
. 17 None None None None
18 115/115 83 0.27/0.25 0.53 * Severe Flushing
69
-......~ 0
Table 22. Theoretical and Measured Asphalt-Rubber Relative Viscosity.
Rubber Content, %
22
24
26
1Ei nstei n
2Brinkman
3Mooney
Measured Relative Viscosity
Torque Fork
1.85
2.23
2.60
nrel = exp(2.5 ~)
nrel = (1 - ~)-2.5
n 1 = exp( 2.5~ ) re 1-1.91~
where,
Calculated Relative Viscosity, n 1 re
Einstein1 Brinkman2 Mooney3
1.73 1.86 2.58
1.82 1.99 3.03
1.92 2.12 3.64
~ = rubber percent by volume
CHAPIER VI
LABORA'IDRY TESTS
Three laboratory tests were used to evaluate physical properties of
asphalt-rubber blends prepared at both test roads and in the laboratory.
The mixer used to blend asphalt and rubber in the laboratory also served
as a rotational viscometer to evaluate rheological characteristics during
blending.
The following chapter discusses the equipment used to test laboratory
properties of asphalt-rubber blends. With the exception of the Haake
rotational viscometer, testing equipment described herein represent
custom fabricated or modified devices not commercially available.
However, each device has been used in essentially s~ilar form in other
research where application of each has been demonstrated (6,7,8,9,17,18).
A laboratory mixer of this type was first used for asphalt-rubber
blending in 1977 (6). The system consists of a constant speed motor with
stirrer assembly which is capable of recording torque chanqes as load
varies on the stirrer. The resulting apparatus is a rotational
viscometer which can measure relative changes in fluid viscosity during
mixing. One difference between this device, shown in Fiqure 21, and
commerically available viscameters is the speed at which mixing and
viscosity readings occur, 500 RPM. Also, this device uses a mixing
propeller for agitation and is prUnarily intended to be a mixer.
There is one difference between the device shown in Figure 21 and the
prototype developed earlier ( 6). 'Ihe oevice described here is fitted
with a glass and teflon bearing where the stirring shaft enters the
reaction kettle. This bearing assures a closed mixing environment to
ensure a minimum of volatile loss during mixinq.- The mixer was altered
71
-....J N
Variable Torque Constant Speed Motor
Electric -----~ Heating Mantle
Speed Controller-~ Torque Output
-.-
Figure 21. Torque Fork Mixer
~ 2000 ml Reaction ·Kettle
: Proportional Temperature Controller
to include this feature at the recommendation of the oevelopers of the
earlier prototype ( 6).
Temperature of the blend is proportionately controlled and heat
transfer is accanplished by an electric mantle surrounding the reaction
kettle.
Procedure
Asphalt cement obtained during test road construction was stored at
OF. S~ling was accomplished by fracturing the cold, brittle asphalt and
transferring an appropriate quantity to the reaction flask for meltinq
prior to addition of rubber. The asphalt was slowly stirred durinq
heating to avoid local overheating. Mixer speed was increased to 500 rpn
when all asphalt had become liquid.
Upon reaching the desired digestion temperature, rubber was added to
the heated asphalt cement in the desired proportion by weight of blend.
Addition of rubber was as rapid as possible, requirinq approxnnately 10
seconds. Digestion t~ was recorded beginning after all rubber had been
added to the asphalt.
Upon completion of blending all asphalt-rubber was removed from the
reaction flask and separated into 6-ounce ointment tins. The material
was cooled to room temperature and "frozen" prior to further testing.
Recording of mixture temperature and relative viscosity was
accanplished throughout blending by strip chart recorder. Mixer speed
was maintained at 500 rpm throughout the mixing process.
Preparation of blends for evaluation by force ductility and softeninq
point was accomplished for the three levels of digestion as shown below:
• t
Low
Moderate
High
Blending Conditions
Tem~rature, F
325
350
375
73
- Time, min.
30
60
180
Haake Viscometer ---------o141 A Haake portable rotational viscometer model VT-02 was used in the
field and laboratory to determine the viscosity of both laboratory and
field mixed asphalt-rubber blends. 'Ihe :Haake. is a simple device which
measures viscosity by t~e same principle as the torqlie fork mixer, except
changes in torque are· monitored by deflection of a calibrated spring
rather than by increases in electrical current as with the torque fork.
The Haake consists of a constant speed motor to which a cylindrical
viscaneter cup is attached. 'Ihe cup is suhnerged in the fluid which
viscosity measurements are desired and the motor started. Draq forces on
the cup as it rotates in the fluid are transmitted to the calibrated
spring within the viscometer. 'Tiscosity is measured directly in poises.
A scale on the face of the instrument is calibrated in poises for fluid
viscosity from 0.3 to 4000 poises. Three scales on the instrument face
correspond to three sizes of viscosity cups sized proportionately for
various fluid viscosities. Figure 22 shows a Haake viscometer with a
Number l viscometer cup.
Procedure
Laboratory prepared mixes were tested after combining asphalt and
rubber by blending in the torque fork apparatus. Field prepared mixes
were tested in the field prior to application on the test sections.
Results appear in Tables 10 and 15 and Figures 17 and lq for El Paso and
Buffalo mixes, respectively.
Asphalt-rubber was obtained in the field by fillinq a one gallon
sample container from the spray bar of the distributor truck. The
viscometer cup was inmersed. The sample was stirred using an aiTOC>red
thermometer for 30 seconds. The temperature was recorded, the viscometer
cup was attached to the viscaneter and the viscaneter motor started. A
74
~
cu -cu E 0 u Cl)
>
75
~
cu -cu E a. 0 :) uu "' >
.... cu -cu E 0 u Cl)
> cu
...:.:: 0 0 J:
N N
rapid rise in the viscosity reading is noted Dnmediately after startinq
the viscometer motor. This is believed to be due to inertial forces
during acceleration of the viscometer cup. As cup velocity becomes
constant, viscosity readings beccme constant. Viscosity readings were
taken at this time, approx~ately three seconds after starting the
viscometer. After approx]mately three to five seconds, viscosity
readings begin to decrease. ''iscosity continues to decrease until the
asphalt-rubber begins to cool, when readings rise again. 'Ihe lack of
homogeneity of the asphalt-rubber mixes may be responsible for the~
observations. All readings reported here were taken three seconds after
starting the viscometer motor.
Laboratory blended asphalt-rubber was tested by ~rsing the
viscometer cup in the blend after digestion in the Tbrque Fork Mixer.
The procedure for obtaining viscosity data was as for field prepared
blends.
Fore~ QH<;tility
The force ductility test is a modification of the asphalt ductility
test ( 16 ). The test has been described ( 6 , 17) as a means to measure
tensile load-deformation characteristics of asphalt and asphalt-rubber
binders.
The·test is performed as described by AS!M Dll3 (16) ·with certain
changes. The principal alteration of the apparatus consists of addinq
two force cells in the loading chain. Figure 23 shows the modified
ductility testing machine with load cells mounted parallel and in direct
line of loading with test spectmens. Spec~ens.are maintained at 39.2F
(4C) by circulating water through the ductility bath during testing.
A second major alteration of the standard ~~TM procedure involves the
test specimen shape. A standard ASTM specimen is as shown in Figure 24.
The mold is modified for force-ductility testing by fabricating new
pieces a and a'. Figure 25 shows the force-ductility mold with modified
pieces a and a'. This mold produces a test specimen with a constant
76
"""-~ "'-J
Ductility Test Frome---and Constant Temperature Both
..,__ __ Thermometer
: Test Specimens
)----Load Cells
:--Output to Recorders
Figure 23. Force- Ductility Testing Machine
• II. 9 em t 0.1 em I•
3. 15 to 3. 2 5 c m
0. 55 to 0.65 em 0.68 to 0. 72 em
1~1___._1 --L.-......J...J.I ;.&-I ~~1.:...4: 1____..1__,_1 ......~1_,1 I 0. 99 to I. 0 I c m
Figure 24·. ASTM D 113 Ductility Mold
11.9cmt0.1cm
0. 55 to 0.65 em
....... II_· ~~ __.__......J...J.I l~l -~~..:...~.! 1____.1..........,1 __.1~......~1 ~99 to 1.01 em
Figure 25. Force -Ductility Mold
78
cvoss-sectional area for a distance of approxDmately 3 centDmeters. This
mold geometry produces a deformation rate of o. 74 + 0.01 an/min. between .. the gage marks of the test specimen at ·a fixed grips test rate of 1
em/min.
Force data is transferred from the load cells to analog recording
equipment. Signals received by this equipment are then transferred to a
microcomputer. Data are stored on magnetic computer disks f.or later
reduction and analysis. Individual components of the force-ductility
apparatus are shown in Figure 26.
Raw data obtained from the force ductility machine are initially in
terms of a force-tDne relationship. However, the constant deformation
rate of 0.74 em/min. allows conversion of force-time information to
force-strain data. Stress data is calculated using the initial one
square centimeter cross sectional area. True stress is obtained by
calculating the change in cross-section as the specimen increases in
length. Engineering strain is obtained by dividing the change in gauge
length by the original gauge length as follows:
~ =--0-
Ee Lo
True strain is obtained by sunming all engineerinq strains and evaluating
the limit as L 0 approaches zero or,
L dL~ sL = f ...-.£ = ln (L) - 1n (L )
L L o. 0 0
L + ~L = ln (_1_) = ln ( 0 0
L L 0 0
Modulus of elasticity was determined by evaluatinq the slope of the
stress-strain curve. 'IWo slopes were evaluated. 'Ihe initial slope of
the stress-strain curve in the linear reqion under primary loading will
be referred to as the "asphalt modulus". A. second slope was observed for
certain blends which was characterized by secondary loading and will be
79
~ Circulating -Water Both
,__--Force-Ductility Testing Machine
·Figure 26. Force- Ductility Testing Apparatus
.._,. __ Force Cell Signal Conditioner
---- Chart Recorder and Analog/Digital Converter
11::: Microcomputer
referred to as "asphalt-rubber modulus" • An example of a typical
stress-strain curve which depicts these parameters is shown in Figure 27.
Procedure
Asphalt-rubber was heated with constant stirrinq to 375F on a hot
plate. TWo specLmen molds were assembled on a brass plate and, to
prevent sticking, the plate and interior surfaces of pieces
were coated with a glycerin-talc mixture. The heated asphalt-rubber was
poured into the prepared molds from end to end until the molds were more
than· level full. The filled molds were allowed to cool to roam
temperature for 15 minutes and then placed in the water bath at test
terrperature of 39.2 F for 15 minutes. 'Ihe excess asphalt-rubber was then
tr~ed with a hot putty knife to make each mold just level full. The
trimmed specimens were returned to the water bath for 30 minutes before
testing.
Side pieces a and a' were detached and the test spec~ns were
removed from the brass plate. Each specUnen was attached to a load cell
and to the movable ductility testing carriage. Excess slack in the
loading system was removed by recording a 0.10 pound load on each load
cell. Testing proceeded at 1 em/min. fixed grips rate until both
specbnens ruptured.
Software written to accomplish data transfer and reduction from the
Hewlett Packard 86R microcomputer is included in Appendix c.
I£uble J3Jll~ qqf1;~n.ing Jbipt
This test is based on a concept proposed by Krchma (18) for
characterization of asphalts. It is a modified version of the ASTM Rinq
and Ball Softening Point Test (19).
The double ball softening point test apparatus consists of two 3/8
inch diameter stainless ball bearings cemented together with the test
material. One of the ball bearings is fixed to the ring holder of the
81
en Q.
... en en Q) ._ ... en
QJ ::s s...
......
Asphalt-Rubber---Modu Ius
---Asphalt Modulus
True Strain, in/in
Figure 27. Representative Asphalt-Rubber Stress- Strain Curve
82
standard ring and ball assembly, the other ball is suspended from the
first by the test material. Figure 28 is a schematic representation.
Heat is applied to the immersed assembly in the manner described by
ASTM (19). As temperature rises in the apparatus, the weight of the
lower ball begins to stretch the asphalt-rubber specimen. Double ball
softening point is recorded as the temperature in the bath between the
specimens as each suspended ball reaches the bottom plate of the
assembly.
Procedure
'A custam mold was fabricated to produce test specimens as shown in
Figure 28. A block of aluminum was drilled and bored such that the
height of the block was·equal to the total length of asphalt-rubber
specimen and attached ball bearings. The block is split to allow·removal
of the specimen. A ball bearing was inserted in a bored hole in the
aluminum block. The block was positioned such that the ball lies at the
bottorn·of the bored hole. A sample of asphalt-rubber heated to 375F was
placed in the bored hole filling the space above the lower ball bearing.
The top ball bearing was inserted in the bored hole and pushed down until
the top of the bearing was flush with the top of the alumim . .rrn block.
Excess asphalt-rubber exuding from around the ball bearings was removed.
The molded specimens were allowed to cool at room temperature for 30
minutes, the halves of the aluminum block were separated, and the test
specimens placed in a 39.2F water bath for 60 minutes.
TWo spec~ens were tested in each beaker by suspending the upper ball
from a maqnet fixed in the ring and ball support stand. The support
stand containing test specimens and thermometer were immersed in 3q.2 F
. water in the beaker and testinq bequn. 'Iesti.nq progressed after this
point in accordance with procedures described by ASTM 036 (19).
83
800ml Beaker
5/811
(4) 3/811 4>
Ball Bearings---++-~~----
0 . ..
Ring and Ball Support Stand
.M---+-~1--++--- Fixed Top Ball
,.....-++--++---Test Specimen
. .,..-+1--++---- Suspended Lower Ball
1- /1611
----t+--- Bottom Plate
.....--- Hot Plate
Figure 28. Double Ball Softening Point Apparatus
84
CHAPI'ER VI I
IAOORA'IORY TEST RESUL'IS
Force ductility and double ball softening point were performed with
asphalt-rubber mixes prepared in the field and in the laboratory.
Laboratory mixes were prepared usinq the Tbrque Fork Mixer. All testinq
was performed using a completely random sequence to minnnize bias and
help assure assumptions of analysis of variance were met. The following
test results have, therefore, been analyzed assuming normal and
independent random errors with homogeneous variance.
All laboratory blends of asphalt-rubber were prepared in the torque
fork as previously described. Twenty-seven blends were prepared for all
combinations of variables as shown in Figure 6. OUtput from the torque
fork is in terms of millivolts of electromotive force required to
maintain a stirring speed of 500 rpm. This output is shown in Figures 29
to 31 for blends with 22 percent, 24 percent and 26 percent rubber by
weight. Although millivolts may be useei for a relative canparison of
viscosity between blends, a more desirable unit of viscosity would be a
poise or stoke. Therefore, a relationship between millivolts output and
poises was established. This relationship should be used to canpare only
general correspondence between millivolts and poises for asphalt-rubber
since the 'calibration' was accomplished with AC-10.
The AC-10 asphalt from the El Paso Test Road was stirred at 500 qm
using the torque fork at a ranqe of temperat~res. The resultinq output
in millivolts was recorded. Viscosity at a ranqe of terrperatures was
determined using a Brookfield viscometer. A relationship was then
determined between Brookfield viscosity and torque fork millivolts for
this AC-10 asphalt as shown in Fiqure 32. Approxnnate viscosity of
85
-0 .s::. ~ ., <(
c: fl)
CD -CD 0 ~ > -CD m E fl)
oa .. c: .... ., CD
0 .a
00 • .a
-....J a: ~
0: CD I
::t -cr 0 .... ~
.s::. ~ .,
c: <( ., CD c: u 0 c: CD .... .! .... 0
50
40
30
20
M
RUBBER A
• • • •.• • • • • RUBBER B ------- RUBBER C
.. .... ·: ..... ............ . . . .......... ~ -----=--=-:=--=-----~-==--::-::.:_::_:.,.. __ -_--_,.~,."!'-·-- H H ,,"'"' • • I
,, .... --------"'"' • • • • • H
,, ,, ,, ,,.
10 L~ ,~L ,, M ~. ~ ,,/-~·-- ,, : ... ,,, --.... ---,, ,'~---... I ,, I,,
~·' r, • Digestion levels as noted
0 L---~----~----~----~----~----~----~----~--~----~ 0 20 40 60 80 100 120 140 160 180 200
Elapsed Time Since Addition of Rubber, minutes
Figure 30. El Paso Torque Fork Output - 24 Percent Rubber
50
-0 .c
40 Q. en
<{
c: en CD -CD 0 :. > -CD m en E ·3o 0 c: ... - CD ,.,
.,g 0 .,g 00 CD :a 00 a:: a:: CD I - 20 :J 0' 0 ... .c 0 Q. ~ en
<{
~ ,., CD c u 0 c:
10 cu .. cu --0
0 0
M
M
RUBBER A
• • • • • • • • • RUBBER B
------- RUBBER C
,-~--------------------------- H ...... ~,M • _,
~- . . , .... L •••• ~ _._._._........ ,, .·· ,, ---- ~-, . . . ,,, ,, ·. ,,' ,, ...... . I ,, • • • • • • • • • • • • • • • • • • • , , .. .. . . ..
/ , ·.·· I I
I II I I ,',
~' / ,, ~~ , L , ,,
I ,, 1,,
·20 40
• Digestion levels as noted
60 80 100 120 140 160
Elapsed Time Since Addition of Rubber, minutes
••• H
Figure 31. El Paso Torque Fork Output -26 Percent Rubber
H
180 200
400------------------------------~------
300
., c» ., ·s 0. .... c c» u
al > 200 ~
::illolll .... ., 0 u ., > "0 c» ..... ~ 0 0 ~
CD 100
~- v8 = 0.003 exp (0.424 VrF)
R2 = 0.99
0 ~------~------~--------~------_.------~ 20 22 24 26 . 28 30
Torque Fork Reading, VrF, millivolts
Figure 32. Re lotion ship Between V TF and V a
89
asphalt-rubber can be ctetermined usinq this relationship for millivolts
and centipoises.
Data from Fiqures 29 to 31 were analyzed by regression techni~1es to
yield the simplified results shown in Figure 33. All data from each of
Figures 28 to 30 were used to generate curves representing mixtures
containing 22 percent, 24 percent, and 26 percent rubber, respectively.
Although the correlation coefficient for each curve is low, a trend to
increased viscosity with increased rubber content is apparent. 'Ih·is is
not an unexpected result since higher percentages of solids in liquid
media have been shown theoretically to increase relative viscosity for
mixtures of colloids in low concentrations (20). · The viscosi~y of each
blend follows a power function reaching approx~ately constant viscosity
from 40 to 60 minutes after the addition of rubber to t~e hot asphalt. A
simple mixture of solid particles in liquid would be expected to increase
viscosity relative to the rate at which the solid was introduced (20).
Therefore, the rapid rate which rubber was added to the blends should
produce a corresponding rapid increase in viscosity. However, a
relatively long period was required for the viscosity of the
asphalt-rubber blends to increase and stabilize at relatively constant
viscosity. This may suggest two things. First, approximately one hour
may be required for the rubber to be wetted by the asphalt such that the
relative viscosity.of the blend can be measured by the torque fork.
Second, some form of reaction may be occurring between the asphalt and
rubber which raises viscosity beyond that explained by theory (7,20).
An attempt at explaining this phenomenon was made by calculating the
relative viscosity for asphalt and rubber blends with 22 percent, 24
percent, and 26 percent rubber. Several models are available which
predict the increase in viscosity of fluids with addition of solids.
Available models which predict viscosity change are based on empirical
adaptations of the Einstein relationship for relative viscosity,n rel = n/n0 , where n is the mixture viscosity and 0 is the viscosity of the
continuous phase. As concentration, particle sh~pe and viscosity change,
the original Einstein model becomes inapporopriate. Various adaptations
of this original :rrodel have been proposed which better predict the actual
90
50
40
en -0 > --E
... 30
~ 4
~'J.,o.z.g ft'l.:::. o.45
1 ~ 7.9 --------------- ---- ~ 26Percent
Q) CJ' c 0 .c u \0 ~ t--1 -en 0 / 0.25 2-046
y = 5.34(Xl R - · 22 Percent
/ y :::.G.IIl){)0 ·30 R'l.:o.41
- - - - - - - - - -- - - - -- - 24 Pe ,.. -- - rcent
~ ~
20
u en
>
0~--~----~--~----~----~--~----~--~----~--~~ 0 20 40 60 80 100 120 140 160 180 200
Elapsed Tim·e After Addition of Rubber, minutes
Figure 33. El Paso Torque Fork Viscosity
viscosity behavior of mixtures. 'lWo such models as well as others are
discussed by Frisch and Simka (20) and are includerl in Table 22 for
comparison with values for relative viscosity obtained using the torque
fork.
Relative viscosity is calculated based on rubber perce~t by volume in
the blend. Specific gravity measurements of asphalt-rubber blends at
various temperatures indicate that volume increases by asphalt-rubber
blends at elevated temperatures can be explained-by thermal coefficient
of expansion calculations as shown in Fiqure 16. Rubber volume was,
therefore, determined using a calculated increase in volume using
constants of thermal coefficient of expansion.
~brk by others (7) to determine rubber volume change in asphalt
indicates that larger volume changes 6ccur when rubber is bnmersed in
heated oil than in asphalt. Such fluids as Califlux G. P., Dutrex 739
and Ibcal 166 have been used to produce rubber volt.nne changes of 50
percent to 100 percent. Wbrk in this proiect estimated similar results
for tread and sidewall truck tire rubber when immersed in SAE lOW motor
oil at 400 F. Rubber cubes initially measuring approxnnately one
centimeter were measured with calipers after 0.25, 2, and 6 hours in the
heated oil. Figure 34 depicts the increase in volume measured for the
two types of rubber. Note from Figure 34 that after two hours a 30 to 38
percent increase in rubber volume over that expected from thenmal
expansion takes place. 'nlis has also been observed by others ( 7)
however, this high volume increase seems to occur only for rubber in oil.
Rubber in asphalt appears to increase in voltune only slightly as shown in
this experiment by specific gravity measurements, Figure 16, and the
excellent agreement of theoretical and measured viscosity data, Table 22·.
The Rrinkrnan equation appears to predict measured viscosity of
asphalt-rubber best. This correspondence is apparently due to accountina
by the model for addition of individual particles to the.dilute
suspension until ·a concentrated suspension is developed.
92
80
-c Q) u ~ Q) a. 60 ... Q) C/)
0 Q) ~
u c -
\0
Q)
E 40 w ~
0 > ~
Q)
.0
.a ~ 20 a:
Thermal Expansion at 400 F
0 2 3 4 5 6
Time, hours
Figure 34. Rubber Volume Change in Oil at 400 F
~grce Dqc.tili ty
Seven test responses appearinq in Table 23 were measured from results
of each force ductility test for both field prepared and laboratory
prepared mixes. Multiple analysis of variance (ANOVA) techniques were
employed to determine whether differences in material properties could be
measured between the various f~ctors investigated.
El Paso Mixes
Results of all tests appear in Appendix D, Tables D1 to 014. Values
shown in Appendix 0 represent an average of two test results obtained
during testing. A surrmary of AOOVA results from lab mixes appear in
Table 23. Table 23 contains statistically significant test results at
· alpha ~ o.os for test parameters and corresponding exper~ntal factors.
Table 24 provides snnilar information for results of field pre~red
asphalt-rubber mixes evaluated by force ductility.
After judging differences between control variables significant at
alpha5 0.05, the Newman-Keuls (21) multiple comparison procedure was
used to judge which treatment means contributed to the significant ANOVA
results. Newman-Keuls analysis was applied when ANOVA indicated
significance as shown in Tables 23 and 24. The results of the
Newman-Keuls analysis appear in Tables 25 and 26 for laboratory and field
prepared mixes.
Buffalo Mixes
Analysis of variance results for seven response variables appear in
Tables D15 to 021 for field mixed asphalt-rubber and Tabl~s D22 to 028
for laboratory prepared asphalt-rubber mixes. These ANOVA results have
been summarized as for the El Paso data in Tables 27 and 28. Entries in
these tables are alpha values for alpha ~ 0.05.
Note that for Buffalo field mixes, a significant difference between
replicates is rejected at alpha ~ 0.05. However, significance between
94
\0 U1
Table 23. Statistically Significant Results of ANOVA for Force Ductility Test Measurements of El Paso Lab Mixes.
Source Max. Max. of Engineering True
Variation Stress Stress
Rubber 0.05 0.01
Concentration 0.03
Digestion
Alpha Level F = F test crit
Max. Engineering
Strain
0.0001
0.0001
Max. True
Strain
0.0001
0.0001
Curve Area
0.001
Asphalt Modulus
0.02
0.004
0.0001
AsphaltRubber Modulus
0.01
0.03
Table 24. Statistically Significant Results of ANOVA for Force Ductility Test Measurements of El Paso Field Mixes.
Source of
Variation
Rubber
Concentration
Max. Engineering
Stress
Max. True
Stress
Alpha Level Ftest = Fcrit
Max. Engineering
Strain
0.002
Max. True
Strain
0.003
Curve Ar.ea
Asphalt Modulus
AsphaltRubber
Modulus
0.04
Table 25. Results of Newman-Keuls Analysis of Force Ductility Test Measurements for El Paso Lab Mixes.
Force-Ductility Parameters
Max. Max. Max. Max. Curve Asphalt Asphalt-Engineering True Engineering True Area Modulus Rubber Stress, psi Stress, psi Strain Strain, psi psi, Modulus, psi
(MES) . (MTS) in/in (ESF) (TSF) in/in (CA) (AM) {ARM)
A 24.5{xy) 80.3{x) 3.67{x) 1.54{x) · 73.6(x) 219.0{xy) 56.8{x) S-
~ B 20.8(x) 87.9(x) 4.61{y) ..0
1.72(y) 78.2(x) 186.7(x) 75.2{xy) :::3 a: c 24.2{y) 118.2(y) 4~92(z) 1.77(z) 105.4(y) 249.1(y) lOl.l(y)
\0 Q"\
... s:: 0 22 27.8(y) 259.3(y) ...... ......, rtS
213.1(x) S- 24 23.8(xy) ~ s:: Q)
181.4(x) u 26 20.9(x) s:: 0 u
s:: L 4.11(x) 1.62.(x) 272.l(y) 61.5(x) 0 ......
4.24(x) 1.65(x) 210.5(x) 73.3(xy)
• -rr·l., \ 171.1(x) 98.2{y)
\0 -.......!
Table 26. Results of Newman-Keuls Analysis of Force Ductility Test Measurements for El Paso Field Mixes.
~ OJ
..0
..0 ::::l
0:::
... c 0 .,... +l tO ~ ~ c OJ u c 0 u
A
B
c
22
24
26
Max. Engineering Stress, psi
(MES)
Max. True
Stress, psi (MTS)
Force-Ductility Parameters
Max. Engineeri-ng _
Strain, in/in (ESF)
4.38(xy)
3.72(x)
3.71(x)
Max. · True Strain
in/in (TSF)
1.68(y)
1.55(x)
Curve Area, psi (CA)
Asphalt Modulus
psi (AM)
AsphaltRubber
Modulus, psi (ARM)
43.6(x)
74.8(y)
65.7(xy)
\0 00
Tab 1 e 27. Statistically Significant Results of ANOVA for Force Ductility Test Measurements of Buffalo Lab r~i xes.
Alpha Level Ftest = Fcrit
Source Max. Max. Max. Max. Curve Asphalt Asphalt-of Engineering True Engineering True Area Modulus Rubber
Variation Stress Stress Strain Strain Modulus
Concentration 0.001 0.01~
Digestion 0.0001 0.0001 0.0001 0.0001 0.0001 0.0001 0.001
D X C 0.01 0.05 0.001 0.03
Table 23. Statistically Significant Results of ANOVA for Force Ductility Test Measurements of Buffalo Field Mixes.
Source of
~Variation
Max. Engineering
Stress
Concentration 0.03
Digestion
Replicate
0.005
Max. True
Stress
0.02
Alpha Level
Max. Engineering
Strain
0.01
0.0001
F = F test crit
Max. Curve Asphalt Asphalt-True Area Modulus Rubber
Strain Modulus
0.02 0.04
0.0002 0.02~ 0.01 0.01
digestion periods and between rubber concentrations is detected using
parameters MES, MTS, and ARM.
Different digestion periods for laboratory mixed asphalt - rubber
produces highly siqnificant ANOVA results for each parameter tested as
shown in Table 27.
Asphalt-rubber modulus {ARM) indicates significance for concentration
and digestion. 'Ihis is the only parameter which identifies significance
for both of these factors in both field prepared and laboratory prepared
mixes.
Newman-Keuls analysis was used for Buffalo mixes to determine which
levels of factors were significantly different as described by ANOVA.
This analysis is trivial for Buffalo field mixes since only two levels
were measured for each factor. Results are shown in Table 29 such that
trends present in the data can be more easily observed. The results of
the Newman-Keuls analysis for laboratory prepared mixes appear in Table
30.
nqub~e Ball _Sof~ening E9int
Analysis of variance was used to judge the precision of the new
double-ball softening point test. Results of these tests appear in
Appendix D, Tables D29 and D30 for El Paso materials and Tables D31 and
D32 for Buffalo materials.
El Paso Mixes
ANOVA results for laboratory mixes indicate no significant
differences for main factors or interactions at an alpha level of o.os. The test is sensitive to rubber type at an alpha level of 0.18 and to the
rubber-digestion interaction at alpha = 0.14.
ANOVA results for field mixed material indicate sensitivity for
differences in rubber concentartion at alpha= 0.18 and. to
rubber-concentration interaction at alpha = 0.06.
99
Table 29. Results of Newman-Keuls Analysis of Force Ductility Test Measurements for Buffalo Field Mixes.
0 .,... ~ E 18 ~ c: ~ 22
1--' c: 0 0 0
§ L .,... ~ VI Q) en o H
Max. Engineering Stress, psi
(MES)
8.6(x)
18.7(y)
14.7(y)
7.7(x)
Max. True
Stress, psi (MTS)
63.4(y)
42.7(x)
Force-Ductility Parameters
Max. Engineering
Strain in/in (ESF)
6.3(y)
5.5(x)
5.1(x)
6.6(y)
Max. True
Strain (TSF) in/in
2.0(y)
1.8(x)
1.8(x)
2.0(y}
Curve Area,
psi (CA)
59.4(y)
41.6(x)
Asphalt Modulus
psi (AM)
113.8(y)
51.8(x)
AsphaltRubber
Modulus, psi (ARM)
33.7(x}
48.3(y)
44.8(y)
32.2(x)
.. s:::: 0
•r-~ fa s... ~ s:::: QJ u
1--' s:::: 0 0 1--' u
s:::: 0
•r-~ VI QJ C')
•r-0
Table 30. Results of Newman-Keuls Analysis-of Force-Ductility Test Measurements for Buffalo Lab Mixes.
18
22
L
M
H
Max. Engineering
Stress (MES )·
19.5(z)
12.8(y)
6.5(x)
Max. True
Stress, psi (MTS)
65.3(y)
64.9(y)
34.5(x)
Force-Ductility Parameters
Max. Engineering
Strain in/in (ESF)
4.32(x)
5.73(y)
6.46(y)
Max. True
Strain (TSF) in/in
1.67(x)
1.90(y)
2.01(z)
Curve Area
ps1 (CA)
67.9(y)
62.7(y)
35.3(x)
Asphalt Modulus
psi (AM)
'94.0(y)
52.6(x)
125.1(z)
27.8(y)
41.5(x)
Asphalt-Rubber
Modulus, psi (ARM)
-33.9(x)
44.9(y)
37.5(x)
52 .. 2(y)
28.7(x)
Buffalo Mixes
The double ball softening point test appears sensitive to changes in
the Buffalo material. ANOVA results for field prepared mixes shown in
Table D32 indicate that the test is sensitive to changes in rubber
concentration and ctigestion conditions with highly significant test
statistics. Asphalt-rubber mixes were replicated in the field and this
factor was evaluated by ANOVA as shown in Table n32.
Replication appears significant at alpha = 0.07. This indicates that
although care was taken to prepare identical replicate test sections in
the field, differences exist between these replicates ·which cannot be
explained purely by chance.
Similar results for lab prepared Buffalo mixes are shown in Table
D31. ANO~ results indicate that the softening point is highly sensitive
to rubber digestion and concentration conditions and less sensitive to
the interaction of these factors. Newman-Keuls analysis indicates the
softening point obtained from the high digestion mixes is significantly
different from softening point results for materials fabricated at low
and medium digestion levels. The trend appears to be toward a lower
softening point as digestion level increases as seen in Table 31. '!he
same trend appears for field prepared mixes as shown by Table 32.
Softeninq point increases as rubber concentration increases, and the
significant interaction of concentration and digestion suggests that
softening point for low concentration-low digestion mixes may be s~ilar
to hiqh concentration-high diqesti.on mixes. This means that the optimum
behavior of asphalt-rubber mixes may be obtained by a0justing rubber
content and digestion conditions.
Brownsville Mixes
Force ductility and softening point data for field mixes appears in
Table D33. Force ductility and softening point data for lab mixes is
presented in Tables D34 and D41. ANOVA results for Brownsville lab mixes
appear in Table 33. ~11 parameters except engineering and true strain
appear sensitive to changes in laboratory digestion. Newman-Keuls
102
Table 31. Results of Newman-Keuls Analysis of Softening Point Test Measurements for Buffalo Lab Mixes.
Softening Point, F .. £:: 0
•r- 18 113.7 (x) ...., "' s.. ...., 22 118.2 (y) c::~ Q) u £:: 0 u
£:: Low 119.7 (y) 0 •r-...., (/) Med 119.2 (y) Q) C')
•r-
c High 109.1 (x)
Table 32. Results of Newman-Keuls Analysis of Softe.ning Point Test Measurements for Buffalo Field Mixes.
.. Softening Point, F c 0
•r-...., "' 18 114.3 (x) s.. ...., ~ c Q) 22 119.3 (y) u c 0 u
c:: 0 Low ..... 118.9 (y) ...., (/)
Q) High 0') 114.7 (x) ..... c
103
1--' 0 ~
Source of
Variation
Digestion
- --- --
Table 33. ANOVA Force Ductility and Softening Point, Brownsville Lab Mixes
Alpha Level F table = F critical I !
Max. Max. Max. Max. Asphalt- Ibuble Ball Engineering True Engineering True Curve Asphalt Rubber Softening
Stress Stress Strain Strain Area Modulus Modulus ~int
0.01 0.0004 - - 0.0004 0.003 0.001 0.0001
-- -- - -- - . - - ---- ----
results appear in Table 34. Note the inverse relationship between each
parameter .and digestion condition.
Field and lab prepared data are shown in Tables D33 and D41. ANOVA
results indicate digestion affects softeninq point as shown in Table 33
and Newman-Keuls analysis indicates softening point decreases as digestion
increases as shown in Table 34.
105
Table 34. Newman-Keuls All Parameters, Brownsville Lab Mixes.
Parameter-s
Max. Max. Max. Max. Curve Asphalt Asphalt- lbuble Ball 1
Engineering True Engineering True Area Modulus Rubber SOftening Digestion Stress, psi Stress, psi Strain Strain, psi psi Modulus, psi R:lint
(MES) (MTS) in/in (ESF) (TSF) in/in . (CA) (AM) (ARM) (SP)
L 13.05 (y) 78.35 (y) - - 75.13 (y) 79.12 (y) 67.62 (y) 114.82 (y)
M 11.42 (y) 82.35 (y) - - 74.23 (y) 67.72 (y) 75.20 (y) 118.17 (y)
H 5. 94 (x) 26.53 (x) - - 30.26 (x) 40.38 (x) 18.33 (x) 103.73 (x)
--- ~- - - -- - ---- - - ------···-- - -
~ Note: Letters in parentheses of the same type indicate no significant difference by A.~VA at alpha< .05.
CHAPI'ER VI I I
ANALYSIS
Analysis of variance (ANOVA) results discussed previously have been
used to measure sensitivity of force ductility and softening point
parameters. Sensitivity is iudged by the ability to identify differences
in asphalt-rubber properties as rubber type, concentration, and digestion
conditions are varied. Results of ANOVA indicate that not every force
ductility parameter nor softenirx.J point result can detect differences in
asphalt-rubber properties for all test conditions.
It is the purpose of this chapter to isolate those force- ductility
parameters and softening point results which are sensitive to changes in
asphalt-rubber formulation and present these changes as trends in
materials properties.
Significant effects on test responses due to main factors are
summarized in Table 35. Responses are noted in Table 35 which indicate
statistical significance for lab and field data and lab data only between
El Paso and Buffalo materials. Significant responses due to sinqular
main effects are presented graphically in figures to follow. Multiple
effects due to digestion level and rubber concentration for El Paso and
Buffalo mixes prepared in the field and laboratory are also shown
graphically by figures.
Rubber Concentration ~~~~~ .. ~~
The quantity of rubber in the mix affects the properties of failure
strain, asphalt modulus, asphalt-rubber modulus and softening point as
shown in Table 35.
Increasing rubber content of the asphalt-rubber mix causes a decrease
in engineering and true failure strain for both Buffalo and El Paso
mixtures prepared in the field. This relationship appears in Fiqure 35.
Both engineering and ~rue strain are presented in Figure 35, true strain
107
~ 0 00
Table· 35. Test Responses Judged Significant by ANOVA.
Main Factor
Test Road Rubber Concentration Digestion Level
El Paso ·Failure Strain (F) Failure Strain (L)
Asphalt Modulus (L) Asphalt Modulus (L)
Asphalt-Rubber Modulus (L)
Failure Strain (F) Failure Strain (L & F)
Buffalo Failure Stress (L & F)
Asphalt Modulus (L) Asphalt Modulus (L & F)
Asphalt-Rubber Modulus (L & F) Asphalt-Rubber Modulus (L &
Curve Area (L & F)
SOftening Point (L & F) Softening R:>i_nt (L & F)
Brownsville Failure Stress (L)
Curve Area ( L)
Asphalt Modulus (L)
Asphalt-Rubber Modulus (L)
Softening IQint ( L) - ·--- -
Rubber Type
Failure Strain (L)
Failure Stress (L}
Asphalt Modulus (L}
Asphalt Rubber ~ulus (L & F)
Curve Area ( L)
!
F)
being a logarithmic transformation of engineering strain as discussed
previously.
Figure 35 indicates El Paso mixes to have lower engineering strains
at failure than corresponding Buffalo mixes. However, the difference
between Buffalo and El Paso true failure strain for 22 percent mixtures
does not appear practically significant. In fact, the true failure
strain data appear to indicate a general decrease in strain as rubber
content increases independent of proiect location.
Rubber content affects asphalt modulus inversely as shown in Figure
36 for El Paso and Buffalo laboratory mixes. Unlike true failure strain,
asphalt modulus does not appear equivalent for Buffalo and El Paso mixes
at 22 percent rubber. Rather, El Paso mixes have considerably higher
asphalt modulus than corresponding Buffalo mixes.
Asphalt-rubber modulus is directly proportional to rubber content for
Buffalo laboratory and field mixes as shown in Figure 37.
Asphalt-rubber stress-strain curves are canposed of two slopes, i.e.,
asphalt modulus (early loading), and asphalt-rubber modulus (later
loading). Because asphalt modulus and failure strain are decreasing and
asphalt-rubber modulus is increasing with increases in rubber content,
the Buffalo asphalt-rubber stress-strain curves are chanqinq shape as
shown in Figure 38. However, the asphalt-rubber modulus for El Paso
mixtures is not significantly affected by rubber content, and therefore
the shape of the stress-strain curve in Figure 38 changes differently as
rubber content increases.
'!he asphalt-rubber modulus measured for laboratory prepared mixes
compares closely with values measured for field prepared mixes. This
indicates that the laboratory mixing procedure may s~ulate actual field
mixing for the asphalt-rubber modulus parameter.
The Buffalo laboratory and field asphalt-rubber mixes demonstrate an
increase in softening point as rubber content increases as shown in
Figure 39. Note, as with asphalt-rubber modulus, there appears to be no
subjective difference between softening point for laboratbry and field
109
c ....... c
... c 0 '--1--' (/)
1--' 0 C1)
~
:I --0 LL
6
4
2
-. Lab Mixed I Field Mixed •
No significant differences between rubber concentrations
• IJ"''o'o ...... , '•
£1 Paso ·-- - ... --. Buffalo El Paso
·-- - t- - ~- - - •
C' c:
·;:: c: ··-.a c:!: ·a. C/) c:
l&J
c: cu·-::ta ...... t--(J)
0--~----~----~----~--~----~----~-----------18 22 24 26· 18 22 24 26
Rubber Concentration, Percent
Figure 35. Effect of Rubber Concentration on Failure Strain
300 ., ~ .. ., ~
~ 200 "0 0 ~ ~
~ ~ --
100 I 0 s:; ~ .,
<(
·~folo ...........
18 22
Lob Mixed-! Field Mixed ..
•-..... _~;, Poso
-....::: ......._.
24 26 18
No significant differences between rubber concentrations
22
Rubber Concentration , Percent
Figure 36. Effect of Rubber Concentration on Asphalt Modulus
en ~
... en :::)
:)
~ 0 :E .... (1)
..c f-1 ..c f-1 N :)
0:: I -0
.s::. CL en
·<t
75
50
25
._., __ Lab Mixed I Field Mixed •
0\),,o\o •
. •-"" """ \\o\O •
~\) / .,
0~~--~----~----~----~~--~----~--~---18 22 24 26 18 22 24 26
Rubber Concentration, Percent
Figure 37. Effect of Rubber Concentration on Asphalt-Rubber· Modu Ius
t-1
~
II) ., Q) ~ ...
en
Buffalo
increasing rubber percent
/......,.increasing rubber percent
Strain
II) II) Q) ~ ...
en
El Paso
increasing ~
rubber 7 percent ~ 1
I I
r_j__. increasing I I rubber I
percent
I Strain
Figure 38. Change in Stress -Strain Curv·e Due to Increasing Rubber Content
130 • Lab Mixed+ Field Mixed---.
LL.
... 120 .... c: • 0 ,o,~• ,o'~ a.. ~\)~ ~\)~ 0' ., ./ c: c: Q) .... 110
~ ,.._
~ 0
~ (/)
100
18 22 24 26 18 22 24 26
Rubber Concentration, Percent
Figure 39. Effect of Rubber Concentration on Softening Point
prepared mixes. However, this test is less sensitive to chanqes in the
El Paso lab prepared materials with insignificant F statistics for rubber
content, but better sensitivity to rubber type at alpha = 0.18. Better
sensitivity to rubber concentration in F.l Paso field mixed materials
appears at alpha = 0.14 as shown in Table 030.
gigestiol) Leve~
Digestion level had no effect on failure stress for El Paso
asphalt-rubber mixes but did affect Ruffalo mixes prepared in the field
and laboratory and Brownsville mixes. Failure stress decreases as
digestion level increases as shown in Figure 40. True stress for Buffalo
laboratory mixes does not change siqnificantly for low or moderate
digestion but rapidly decreases after hiqh digestion. A. qood correlation
appears again between laboratory and field mixes. Low field digestion
results in failure stress slightly lower than low lab digestion and high
field digestion results in failure stress slightly higher than high lab
digestion.
Failure strain increases with increasing digestion level as shown in
Figure 41. This is opposite to the effect shown for rubber
concentration. This result coupled with that for rubber concentration
indicates that high digestion may cause disintegration of rubber which ·
acts to reduce the solid rubber content of the mix.
A test was devised to extract asphalt from asphalt-rubber mixes using
a procedure described in A...S'IM D2172 Method B to determine if rubber
disintegrates while digested at various levels with asphalt. 'Ihe results
are shown for Buffalo and El Paso asphalt-rubber blended in the
laboratory with 22 percent 'l\'Pe A rubber under the conditions shown:
115
80
60 -(/)
Cl. .. (/)
(/)
QJ
'"--(/) 40 Q.)
"-::J -·-t-' 0 t-'
0" LL..
20
Bro.,msvi~V -t--v- - T Lob MiKed . I Field MiKed
Buffalo \ . ·-- -·\ \ \\ \\.
\, \&
• ........_,_, 13tlffoJo ........___, ........ v __ - ...... --v-- "'• Bro,.,Slti/Je - -v
Low Mod. High
• ' <9"' '\:JQ
~
" '·
•.........._BIIffolo
........ """'• Low High
. Digestion Level
Figure 40. Effect of Digestion Level on Failure Stress.
Cl)
en ~ ... ~ U')
~ ::J ... t-
0 c: ... en ~ ., ~ .. c::: ... ·--g'Ul
LIJ
8
.~ ......... c:: - 6 .. c:: 0 ... ...
t--' (/)
t--' '-I <U ... 4
:I
0 L&..
2
Lab Mixed+ Field Mixed
r,.\o\o ./• ~\) . / /7
,:" E\ paso --- • . -- ;;,..--.--
Buff0\0
·- =--' .:::.-::=. t El Paso
Low Mod. High
0u\\o\O ..,.....• ~,.. .,
Buffalo ·- ~ --· Low High
Digestion Level
Figure 41. Effect of Digestion Level on Failure Strain
c: 0 ... -fJ)
0 c: ... Cl) Cl) c: 0 c: ~
c: 0 .... -fJ)
Cl)
:::J
~
.......... ~~-.... ........ ~ ...... ---··-·-·-.......... -... -·-· -··-·· ...... ··-··-·-·--Test Road
....................................... Jzd ...... . • ........ IIIII'
El Paso .....,.
Percent Percent Percent Percent
Digestion Rubber Rubber Rubber Rubber
Conditions Extracted Loss Extracted Loss ~ .......... ....,.. .................... ~-~----·· rl ········~·· tti ,
1
2 hours @ 350F lA.O 18 18.() 15
4 hours @ 450F lS.l 31 15.2 31
~~ .. l'J.pyrs @ 4 .. ~0F.............. !,!:_.6_. ·-··-· j~· _ .............. 34 __ ,,....., ~--L-SMIJ._,l ____ • ___ 3_1_..,.
These results support data previously presented which indicates that
as oigestion level increases, solirl rubber disintegrates, leaving less
rubber by weight in the mix. Favorable correspondence between lab and
field mixed data occurs for failure strain of Buffalo mixes as shown in
Figure 41.
Asphalt mooulus decreases as digestion level increases for both El
Paso and Buffalo lab mixes and Buffalo field mixes as shown in Figure 42.
El Paso asphalt modulus is significantly higher than Buffalo and
Brownsville lab mixed materials. Buffalo lab and field mixed asphalt
modulus values are comparable as with other response variables. Aqain,
low level field digestion produces a response corresponding to between
low and moderate lab diqestion.
Recall that increasing rubber content produced a decrease in asphalt
modulus as presented in Figure 15. The result shown in Figure 42 is
opposite that expected from Figure 35 since increasing digestion has been
shown to reduce the total solid rubber content in the mixture. The high
digestion (reduced rubber content) mixes would proouce a higher asphalt
modulus than low digestion mixes if reduced solio rubber content was the only
result of high digestion •. 'Ihe apparent disagreement of Figures 36 and 42
indicates that a factor other than rubber content alone may affect
asphalt modulus. Therefore, it is possible that during the process of
digestion, other changes occur in the asphalt-rubber mixture besides a
118
t--1 t--1 \0
U)
a.
U)
::l
::l "0 0 ~ -0 ~ c..
"' <l
300 I
200
100
• Lob Mixed I Field Mixed __ ,...
." f"l p "oso
.........
"· • "'-..
8" ff o I ~ 0 • v--.--- .........__~
Brownsv;uJ'-- -- +
Low Mod. High
Digestion Level
•-....... ... ~fot0 ............._
Low
..............
High
Figure 42. Effect of Diqestion Level on Asphalt Modulus
reduction in solid rubber. These unknown changes may affect the behavior
of asphalt modulus as well as the reduction in solid rubber.
To help identify such changes, asphalt was analyzed before and after
~ixinq with rubber. 'Ihe qel permeation chromatography (G'OC) test ( 22)
was used to identify changes between original asphalt and asphalt after
mixing with n1hber. The GPC test provided data regarding the molecular
weight distribution of asphalt before ann after digestion with rubber.
The results are shown in Figure 43 and depict a shift in the molecular
weight distribution after diqestion. This shift in molecular weiqht of
the asphalt after diqestion indicates that alterations have occurred in
the asphalt during the digestion process as noted by an increase in high
and low molecular weiqht materials. This means that as digestion
continues, some rubber may be lost to the asphalt fraction of the
asphalt-rubber mixture. This has been shown by extraction results
previously and by the increase in both high and low molecular weights as
shown by GPC results in Figure 43. Asphalt modulus as measured by
fo~ce-ductility is evidently sensitive to this change in the asphalt
phase as shown in Figure 42. Therefore, asphalt-rubber evidently is
s~ly not a mixture of solid rubber particles in a continuous asphalt
phase, but a more complicated blend of modified asphalt and particulate
rubber.
Asphalt-rubber modulus produces inconsistent results as digestion
level increases and no general trends are apparent in the data between or
within test road materials as shown in Figure 44. Asphalt-rubber modulus
tends to increase with increasing digestion for El Paso lab mixed
materials but Buffalo lab mixed materials do not demonstrate a clearly
increasing or decre:asing trend. Rather, the Buffalo laboratory mixed
material displays an increase in asphalt-rubber modulus from low to
medium digestion, and a decrease from medium to hiqh digestion. From
Table 28 we see that asphalt-rubber modulus at low and high digestion are
not significantly different values. The Buffalo field mixed material
tends to decrease in asphalt-rubber modulus as digestion level increases.
'Ihis is consistent with Figure 37 which indicates a decrease in
asphalt-rubber modulus as rubber content increases. However, general
120
en ,,
Q) ........... ~Before Digestion =» d u Q)
0 \~After Digestion :E I l ..... 0 ._ I
!---' Q) \ ..c
N E I !---' \ =» z
Q) I \ .~ -0 I Q)
0:::
I
Decreasing Molecular Size
Figure 43. Gel Permeation Chromatography Results
Cl)
a. ...
CJl = :::::» "0 0 :E 100 ~
Q) .0 ..Q ~
:::::» N
a: 50
N
I -0 .c a. Cl)
<l
4 Lab Mixed~ Field Mixed
E.\ ~0so •
0fo'~~"s"i\\e - _... v---;;~, ............. ·--· ........ ' Buffo\O ~
Low Mod. ""· v
High
Buffalo ·-----Low
Digestion Level
•
---. High
Figure 44. Effect of Digestion Level on Asphalt- Rubber Modulus
aqreement hetween Pioures 17 and 44 is not present. 'Therefore, an
explanati.on of the effect on asphalt-rubber modulus clue to a chanqe in
rubber content resulting from hiqh oiqestion appears unwarranten.
Therefore, reasons other than simple reduction of solid rubber content
due to diqestion seem to affect asphalt-ruhher modulus similar to asphalt
modulus.
The area under the stress-strain curve which is a measure of the
touqhness of the blend decreases for Ruffalo asphalt-rubber as digestion
level increases. However, the decrease in curve area does not occur
until after mocterate diqestion has been reached. Curve areas for lab
mixect material at low and Tll()(ierate dioestion are not siqnificantly
different as shown by 1\Tev.man-Keuls results in Table 28 and graphically by
Fiqure 45. Aqain, note the similarity between lab and fielci prepared
mixtures. However, the curve area for low field digestion compares
closer to values for moderate lab digestion than does low lab digestion.
Softening point is affected by digestion similar to curve area as
shown in Fiqure 46. Aqain, as with curve area data, no significant
difference occurs in softening point for low and moderate niqestion
laboratory mixes, but a significant ciecrease in softeninq point is shown
for high diqestion laboratory mixes. Ne\Ai'man-Keuls rlata in Table ?6
verify this. tnterestinqly, failure stress, curve area, and softeni.nq
point rleoict similar trends for low, modera.te and hiqh diaestion levels
for laooratory orepare<i Buffalo asphalt-rubber, and curve area and
softeninq point for Brownsville asphalt-rubber. There was no significant
<iifference between any factors at low and monerate digestion levels, but
a significant decrease is observed for all factors between moderate and
hiqh levels of diqestion.
Diqestion appears to affect softeninq noint at insignificant levels
for P.l Paso lab-ano fielo prepared materials as shown in Table D29.
123
0111: Lab Mixed Brow
Field Mixed
751-~- nsville -·~ffa/o
-v \ -- --·
(/)
'\ I Q. "\
• 0
,s",
Q) "\ I 'Qio
"-
t--1
<( "· N <U \• +:"- >
"- "'V ::l u 25
0--~------~------~--------~------~-------Low Mod. High Low High
Digestion Level
Figure 45. Effect of Digestion Level on Curve Area
130 • Lab Mixed Field Mixed __ ___.
LL.. Buffalo 120 ·-- -· ,.. - 'fllos"\\ \e V' ·--c:
--.Buffalo
0 aro-- -- '\. --a.. v-- " --- --- --· Cfl "" c: -
t-' c: 110 "" N Q)
Vl -- • 0
" V> v
100
Low Mod. High Low High
Digestion Level
Figure 46. Effect of Digestion Level on Softening Point
Rubber type affected the following factors for laboratory anrl/or
field prepareo mixtures as noterl.
Factor ---Pailure Stress
Failure Strain
Curve A.rea
Asphalt Modulus
Asphalt-Rubber Modulus
Lah
Lab
Lab
Lab
Lab anct Field
As noted aoove, significant differences in factors generally were
measure<i for lab prepared mixes, asphalt-rubber modulus being the only
factor affected by rubber type for both lab and field prepared mixes.
Rubber types "A anrl B generally provide the same response from each
factor noted above, the only factor showinq a siqnificant difference
beinq failure strain. The difference measuren for failure strain,
although statistically significant at alpha < o.os, may not he of
practical significance. Table 24 ann Piqure 48 indicate mean true
failure strain for rubber types 'A, Rand C to be 1.114, 1.72 and 1.77
in/in, respectively. All three values are iu<ined statistically
significant. A.lthouqh l.S4 and 1.72 may have J)ractical significance,
1.72 and 1.77, probably do not.
The difference in resoonse between :Rubber Tvpes A ann R ann Rubber
Type C, however, may be considered, not only of statistical significance,
but practical significance as well. F'iqure 47 shows an increase in tn1e
failure stress for Tvpe C over 1\{pes A and R. An increase in curve area
is shown for 1\rpe C over Types A and R in Piqure 49, and 'fVpe C
demonstrates both hiqher asphalt and asphalt- rubber mooulus than 1:ype R
and Type A rubber, respectively, in Figures 50 and 51.
:Recall frorn Table 4 the most significant difference between Rubber
Type C anri Rubber 'T'ypes A and B was the lack of natural rubber in Rubber
c.
126
~ N -.....1
en a. .. en en Q) ... ... (/)
Q) ... ::3 --0 u..
100
50
/ E\ paso / ·-- -·
/ /
• /
--· Et Paso _..-•--- --·.,...-
0 c A 8
Rubber Type
Lab MixedT Field Mixed
., fl) ., ~ -C/) ., :I ~ ....
fl) fl) ., ~ -C/)
C' c: ~ ., ., c C' c: UJ
I
No significant differences between rubber types
Figure 47. Effect of Rubber Type on Failure Stress.
t-1 N co
c ........... c.:
c: 0 "-.... (/)
Q) "-:l
0 LL.
6
4
2 ·-
.. Lab Mixed+ Field Mixed ..
.-- ------. ~0-:,0 ./
~,,.., /
............
El paso ·-- -·-- -·
c: c ... -en D c: ... c» c» c: 0 c w
r: a ... -(/) c» :::s ... .....
No significant differences between rubber types
0 c A B
Rubber Type
Figure 48. Effect of Rubber Type on Failure Str-ain
........, N
""
U1 a.
-0 Q) ~
<:{
Q)
> ~
:J u
100
50
• Lob Mixed I Field Mixed •
/
£.1 paso / ----. ·--
/ /
•
No significant differences between rubber types
0~----------~------~------------------------------A 8 c
Rubber Type
Figure 49. Effect of Rubber Type on Curve Area
~
w 0
Vl a.
300
.. 250 ·-Vl :l
:l 'U 0 ~ -_g 200 a. Vl
<I
150
.,.___Lob Mixed I Field Mixed .,
.......... e-, / A
,oso /
'/ •
• I
No signi ficont differences between rubber types
0----~------~------~-----------------------------A B
Rubber Type
c
Figure 50. Effect of Rubber Type on Asphalt Modulus
• u
I
r I
I • aJ
'0 ' QJ >C 0" ~
(/')
~()()'" ::::s r--
'0 ::::s
/~' ""'0 QJ 0
• <X :E 1.1-
QJ s-a. QJ
>. ..c ..c .._ ::::s
0::: '- I QJ ..j.J
.Q r--
..0 ttS :::J .s:::.
-o a: 0.. (/') QJ • u c:::(
>C
" :E s::: 0
.0 ' QJ
0
" 0..
....J >, r--
1 ' s-QJ • ..c
' ..c
::::s
o\ 0:::
'~
~\ 0
..j.J
~\ u QJ
4--• <( 4--LJ...J
r--L.O
QJ
0 0 0 s-0 \{') ::::s
en W-
ISd 'sn,npo~ Jaqqn~- II 04dsv
131
Combif1~ _Eff~~!:.§l. Concentration ~nd Di.g~stion
Asphalt modulus is affected significantly by both digestion level and
rubber concentration as shown in Figure 52 for laboratory prepared mixes.
Buffalo mixes show the rrost siqnificant effects on asphalt modulus at low
and moderate digestion levels. Asphalt modulus generally decreases with
increases in rubber content and increases in digestion. Only a slight
change in asphalt modulus occurs for high digestion mixes canpared to low
and moderate digestion at 18 and 22 percent rubber. This indicates that
for Buffalo mixes the desired asphalt modulus might be achieved by
chanqing either digestion or rubber content.
The effect of rubber content and digestion on El Paso laboratory
mixes is less clear. At 22 percent rubber, the trend toward decreasing
asphalt modulus with increasing digestion is present. However, as rubber
content increases, this trend disappears as shown in Figure 52. Figure
52 shows the much hiqher asphalt modulus values for the El Paso mixes
compared with Buffalo mixes.
The general trend in asphalt-rubber modulus data shown in Fiqure 53
appears to be toward lower modulus as diqestion increases and rubber
content decreases. This appears tn1e for low and high niqestion Buffalo
mixes prepared both in the field and laboratory. Also, it appears from
Figure 53 that the effect on asphalt-rubber modulus due to rubber content
is less for high digestion mixes than low digestion mixes. '!he effect of
rubber content on asphalt-rubber modulus at moderate digestion appears to
be zero.
Softening point tends to increase with rubber content and decrease
with digestion as shown in Figures 54 and 55 for ~1ffalo and El Paso
mixes. The softening point values of the Ruffalo and El Paso mixes do
not appear to significantly differ at low and moderate diqestion levels
either for laboratory mixes or for field mixtures. Again, the .effect of
rubber content on softening point appears greatest at low digestion
levels for both mixtures whether lab or field prepared.
132
~ w w
300
250
c/)
c. 200 c/)
:l ;:, -o 0 ~ 150 ~
Q) ..0 ..0 :J a:
I - 100 0 .c c. c/)
<l
50
Buffalo
.............
Type A Rubber
Lob Mix
• ',• Low
' ' ' • Mod.
•--- • High
18 22
Rubber, Percent
• \ \
\ \ • Low ,.,. ·--\ .....
.\-' ....... ..._ \
....._e._ 't--- • High
\ \ \
• Mod .
El Paso
22 24 26
Rubber, Percent
Figure 52. Effect of Rubber Concentration and Digestion Level on Asphalt Modulus.
en a.
en ~ -:l
,'0 0
~ ~ (..V ,J:-o ...
Q)
.c
.c ~
a:: I -0
&. a. en
<[
Buffalo Lab Mix Buffalo Field Mix
I 60
•--- -•Mod. • Low
/
/•Low
// / 40
/ / ~ e High
./ ~ ~
.~ ..,....,.... ,...........• High
,..,..,......,. . ...........-.~
20
0------~----------------------~--------------~-----18 22 18 22
Rubber, Percent Rubber, Percent
Figure 53.. Effect of Rubber Concentration and Digestion Level on AsphaltRubber Modulus
120
u.. .. -c:
0 110 a. 0 c:
~ ·-w c: V'l Q,) -.... 0
V)
100
• Low /
/ • --..A --... • Mod.
/ • /• High
/ ./
But tal o
18 22
Rubber, Percent
Type A Rubber
Digestion
, • Low ./ .,.......
• __ .-- -- ) Digestion ·---· •--- e :::.~- e High -..... • Mod .
El Paso
22 24 26
Rubber, Percent
Figure 54. Effect of Rubber Concentration and Digestion Level on Softening Point of Lob Mixes
120 u.
.. -c 0
a_
0'1 110 c
t--' ·-w c 0"\ Q) --...
0 (/)
100
Type A Rubber
.,......,• / . _., /
/ /
./
Buffalo
Low Digestion High
18 22
Rubber, Percent
,..,.. ·- ---· . .,.,.. _,.,
El Paso
22 24 26
Rubber, Percent
Figure 55. Effect of Rubber Concentration and Digestion Level on Softening Point of Field Mixes
Failure strain tends to decrease with increasing rubber content and
increase with digestion for Buffalo field mixes as shown in Figure 56.
This outcome supports the finding that as digestion proceeds, rubber
disintegrates in the asphalt producing less solid rubber by weight in the
mixture and a wider size distribution of molecules.
137
c ........ c
c: 0 ..... -(/) Q) ..... I-'
:::3 l.V 00
·-0 LL
8 Buffalo Field Mixes
t:.-~High
6~ ~
J ~ Low
2 &;; : High Low
c: 0 .... -(/) 0 c: ·-... u • c: ·c;. c:
""
.5 0 ... .. (/)
u :1 .... t-
0--------------------------------------------18 22 Rubber, Percent
Figure 56. Effect of Rubber Concentration and Digestion Level on Failure Strain
CHAPI'ER IX
CONCLUSIONS
1. TWo experimental full-scale test roads containing asphalt-rubber
interlayers were constructed. The arrangement of test sections at
both test roads is such that future correlation between field
performance and laboratory properties of interlayer materials can be
statistically analyzed.
2. Documentation on both test roads is extensive regaroinq initial
pavement condition, construction procedures for asphalt-rubber
fabrication and asphalt concrete overlay production. Material
properties for both interlayer and overlay have been recorded such
that future correlation between laboratory properties and field
performance may be possible.
3. Further development of four new laboratory tests indicate test
results are sentitive to changes in asphalt-rubber composition for
certain asphalt-rubber mixtures.
4. Viscosity measured by the torque fork mixing apparatus compares
closely with viscosity values calqulated using theoretical models.
This means future quality control procedures for determininq rubber
content may be possible by viscosity measurement.
5. Extraction of asphalt from asphalt-rubber mixtures indicates solid
rubber disintegrates in the asphalt-rubber as digestion proceeds.
Results of gel permeation chromatOQ"raphy tests indicate that the
asphalt from asphalt-rubber mixtures contains more high molecular
size and low molecular size molecules than the parent asphalt. This
apparent addition of molecules to the asphalt in asphalt-rubber
mixtures indicates the asphalt has been altered. Rubber is the only
other constituent in the mix which could contribute additional
molecules. Therefore, after diqestion with rubber, asphalt in
asphalt-rubber may contain some rubber components.
139
6. The force-ductility test yields seven parameters which may be used to
predict changes in asphalt-rubber properties due to rubber type,
rubber concentration, and digestion level.
7. 'Ihe force-ductility test used in this study produces a true
stress-strain curve for asphalt-rubber mixtures which has two
characteristic linear portions. The slope of the linear portion of
the curve during initial loading approxUnates the modulus of
elasticity of asphalt cement tested under s~ilar conditions and has,
therefore, been labeled "asphalt modulus". The slope of the linear
portion of the curve during later stages of loading is always less
than that during initial loading and may measure a composite
"asphalt-rubber modulus"~ The slopes of both portions of the
stress-strain curve appear to be a function of rubber content and
digestion level.
8. Strain at failure during force-ductility testing increases as
digestion level increases. Strain at failure decreases as rubber
content increases. Consistent with data are extraction tests which
show solid rubber content is d~inished as digestion proceeds.
Therefore, it seems that an increase or decrease in tensile strain
properties may be achieved with asphalt-rubber mixtures by varying
digestion conditions and/or rubber content.
9. Similarly, asphalt-rubber modulus for some mixtures decreases with
increasing digestion and decreasing rubber content. However, the
effect of rubber content on asphalt-rubber modulus is dUninished as
digestion increases. This suqqests that at some high level of
digestion, rubber content could be increased with no effect on
asphalt-rubber modulus.
10. Stress at failure for the force-ductility test decreases as digestion
proceeds from moderate to high for same asphalt- rubber mixtures.
These results are shown for the area under the stress-strain curve
and the double-ball softening point for the same asphalt-rubber
mixtures. Stress at failure, area under the stress-strain curve and
double-ball softening point appear to measure s~ilar properties for
140
these mixtures and may be useful tools for identifying optimum
mixture properties.
11. Physical properties of some field prepared asphalt-rubber mixtures
appear similar to mixtures prepared in the torque fork laboratory
mixer/viscometer. However, low level field digestion noes not
produce mix properties corresponding to low level laboratory
digestion. Rather, low level field digestion is better approximated
by laboratory digestion conditions intermediate between low and
moderate levels as definerl in this report. Mixes which showed the
best correlation were Buffalo materials tested using softening point
at various rubber percentages and digestion levels. Buffalo
materials showed good correlation at various diqestion levels for
force ductility parameters of failure stress and strain, asphalt
modulus, and curve area. Asphalt-rubber modulus gave good
correlation for Ruffalo mixes prepared at high digestion levels,
only. El Paso rubber types A and B produced similar results between
lab and field mixes when evaluated by asphalt-rubber modulus.
12. The double-ball softening point test is sensitive to changes in
asphalt-rubber sbnilar to certain force-ductility parameters.
However, although double-ball softening point was sensitive to
Buffalo lab and field mixes, it was not sensitive to F.l Paso mixes
from either lab or field. The reason for this discrUnination is
unknown, but may be related to the type of asphalt-rubber tested.
The El Paso materials were visibly more heteroqenous than the Buffalo
materials, probably due to the larger rubber particles. The lumpy
nature of these mixes may be the reason for a lack of sensitivity in
the double-ball softening point test.
13. Asphalt-rubber prepared using Rubber 'J.Vpe C behaved unusually in the
field, foaming resulted in overflow of the distributor. '!his
asphalt-rubber also provided performance differences in the
laboratory. Rubber C was processed cryogenically, and contained no
natural rubber. These are the major known differences between Rubber
C and Rubber A and B. It is unknown whether these differences caused
141
the observations noted herein. A. relationship between asphalt-rubber
rotational viscosity and rubber content has been shown. This
relationship may provide a means of verifying rubber content and
digestion conctitions in the field by measuring rotational viscosity
at the iob site.
14. Tb test whether measurements of this type are practical and relay
meaningful information, the Haake viscometer was used to measure
viscosity of asphalt-rubber at various temperatures after three
levels of digestion. Rubber content of the mixes was measured after
low, moderate and high digestion, and viscosity taken at four
temperatures. Asphalt-rubber tested consisted of 22 percent TYPe A
rubber blends using El paso and Buffalo asphalt and rubber,
respectively. Results are presented in Figure 57.
The dat~ indicates that extractble rubber content decreases as
digestion level increases. This result is consistent with previous
data presented. The data also show, not unexpectedly, that viscosity
increases as temperature decreases. However, more significantly, it
appears that rubber content may be predicted fran Haake viscosity
data at test temperatures below 250F. Figure 57 also indicates
rubber-viscosity curves may be asphalt-rubber type related as shown
by the difference in results at 200F for El Paso and Buffalo mixes.
More testing would be required to produce ~ementable charts which
could be used in the field, but data such as that shown may be
derived for some.typical types of asphalt-rubber mixes~ This type
information would be useful to field personnel responsible for
quality control.
15. Based on observations and measurements made at the three test roads,
certain modifications are recommended to the Texas SDHPT
asphalt-rubber specification. The new recommended specification is
included as Appendix E to this report.
16. A design and construction procedure for asphalt-rubber seal coats and
interlayers should be adopted. This procedure uses fundamental
concepts outlined by Epps, Gallaway and Hughes in TTI Research Report
142
c Cl)
u .... Cl)
Cl.. ~ ....
QJ
..0 D
~ ::::> ..(,:"- 0::: VJ
19
15
I
oo'</ I
I I
&I.
0 10 N
I
I I
MATERIAL
BUfFALO EL PASO
0 • A A
0 •
LAB MIXED
I CONDITIONS J
MIXED AT 350 F FOR 2 HRS. I
MIXED AT 450 F FOR 4 HRS. I
I
MIXED AT 450F FOR 24 HRS. I
____j
Note: All mixes 22 °/o Type A Rubber
~----~~-----·'·------~------~------~------~------~---------------0 250 500 750 1000 1250 1500 1750 2000 2250
Hooke Viscosity, Poi~es
Figure 57. Relationship Between Viscosity and Rubber Content.
214-25 for design and construction of seal coats. However, .
asphalt-rubber seal coats and interlayers can tolerate higher init:i.al
embedment depths, and it is believed these hi.qher embedment depths
contribute larqely to the reflective crack reduction nossible when
using these systems as surface treatments or i.nterlayers. Figure 58
depicts a modified version of the embedment depth qraph from Report
214-25. Initial embedrrent has been increased for seal coats and
interlayers over that for conventional seal coats as shown.
Allowable interlayer embedment is higher than seal coat, but
judgement must be exercized for facilities which must carry traffic
for extended periods prior to overlay construction to avoid excessive
flushing.
144
100
90
so
70
~ 0 60 ,.
t-z w
50 ~ C)
w CD ~ 40 w
30
20
10
0
't:_l 1 I 1 I 1 I 1 I 1 I' I 1 I 1 l 1 J' I 1 11 1_: o- __[Average mot thickness -
~1 -~ oaoaaaaooo -::-l. Embedment T --~ -1- -~
L.. -- .. ~
~ -~ , ,.
~ ~ -.._
~ ~ , -~ ,~ ~ - -- cor>.~s--t .... 1- \.. sE.f>.:-,-~ -~
~,o~~...;...-~ -~~~~l4-~ io-
~ -- •• - ~ 1- .....,-,· -1- --- ASPHA~T-RUBBER INTERLAYER -.,_ 1- ---ASPHALT-RUBBER SEAL COAT -
--KEARBY CURVE -~----
~ ·-• • • BENSON-GALLAWAY 1--o
~ -~. I I I I I I I I I I I I .-
0.2 0.3 0.4 0.5 0.6 0.7 0.8
AVERAGE MAT THICKNESS, IN.
Figure 58. Percent Embedment Determined by Mat Thickness.
145
CHAPTER X
RECOMMENDATIONS
1. Monitor performance of El Paso, Buffalo and Brownsville Test Roads.
As reflective cracking data becanes available meanin<:Jful correlations
between laboratory data presented here and field performance should
be established. These correlations will provide a datum for
desirable laboratory properties of asphalt-rubber mixtures. Future
mixtures can then be designed with appropriate laboratory properties
based on this performance information.
2. Develop a correlation between torque fork rotational viscosity and
portable rotational viscaneters such as the Raake so that data can be
qenerated relating rubber content, digestion level and rotational
viscosity. Field verification of construction conditions should be
possible after collection of sufficient data.
3. Develop a data base of force-ductility parameters for asphalt- rubber
proiects such that field performance can be compared with failure
stress and strain and asphalt-rubber moduli. 1hese correlation data
can then be used with theoretical mechanical models to provide data
regarding a desirable range of values for these parameters. In
conjunction with the apparent relations between rubber content and
digestion level, an asphalt-rubber mixture desiqn method could be
developed. This method would describe various means for producing a
mixture with the desired material properties described by mechanical
modelinq. Production of the mixture could be accomplished by various
means, by varying rubber content and type and digestion conditions.
4. Evaluate asphalt-rubber mixes by force ductility over a ranqe of
temperatures and strain rates. The successful establishment of seven
force ducti.li ty parameters in this research should be extended to
measure temperature and test rate effects on these parameters.
Collection of these measurements at various temperatures and test
rates would facilitate incorportation of such parameters in pavement
146
desiqn models which require parameter description as a function of
temperature and loadinq rate.
s. Expand the force ductility test to provide stress relaxation data.
Ry halting the test after an initial load has been applied to the
test specimen and monitorinq the decrease in load correspondinq to
stress relaxation, two additional parameters can be measured; ·
relaxation modulus, and relaxation tbne. These two parameters are of
~rtance because they allow characterization of viscoelastic and
fracture properties. Further use of these parameters should also be
helpful in pavement structural analysis such that "application
specific" materials can be formulated to solve specific design
problems.
6. Adopt the specification included herein for construction of
asphalt-rubber seal coats and interlayers.
7. Adopt an asphalt-rubber seal coat and inter layer design procedure
based on that outlined in detail by TTI Research Report 214-25 with a
modification to inital embedment depth as described previously.
147
REFERENCES
1. Shuler, T. s., Pavlovich, R. D. and Epps, ,J. A. "Field Performance of Rubber Modified Asphalt Paving Materials", paper subnitted to Transportation Research Board for presentation at annual meeting, Washington, D.C., January, 1985.
2. Way, G. B., "Prevention of Reflective Cracking at Minnetonka - East (1979 Addendum Report)", Report AOOT-RS-15(130), Arizona OOT, Auqust, 1979. .
3. Shuler, T. s., Pavlovich, R. o., Epps, J. A., and Adams, c. K., "Investigation of Materials and Structural Properties of Asphalt-Rubber Paving Mixtures", FHWA Project DTFH61-82-C-0074, Federal Highway Administration, vTashinqton, D.C., March, 198S.
4. Shuler, T. s., Gallaway, B. M., and Epps, lJ. A., "Evaluation of Asphalt-Rubber Membrane Field Performance", Texas Transportation Research Report 287-2, May, 1982.
s. Oliver, J. w. H., "A Critical Review of the Use of Rubbers and Polymers in Bitumen Bound Paving Materials", Interim Report AIR-1037-1, Australian Research Board, 1977.
6. Pavlovich, R. D., Shuler, T. s., and Rosner, J. c., "Chemical and Physical Properties of Asphalt-Rubber", Report AOOT-RS-15(133), Arizona DOT, November, 1979.
7. Green, E., and 'Iblonen, w. J., "Chemical and Physical Properties of A..sphalt-Rubber Mixtures", Report AOOT-RS~14(162.), AOOT, July, 1977.
8. Shuler, T. s. and Hamberg, D. J., "A Rational Investigation of Asphalt-Rubber Properties", University of New Mexico Engineering Research Institute, August, 1980.
9. ,Jimenez, R. A., "Testing Methods for Asphalt-Rubber", Report AOOT-RS-15( 164), AOOT, January, 1978.
10. American Society for Testinq and Materials, ~STM Annual Book of Standards, Part 14, "Concrete and Mineral Agqreqates", 1980.
11. American Society for Testing and Materials, AS'IM Annual Bod< of Standards, Volume 09.01, "Rubber, Natural and Synthetic-General Te.st Methods, Carbon Black", ,June, 1984.
12. Texas State Department of Hiqhways and Public Transportation, 1982 Standard Specifications for Construction of Hiqhways, Streets and Bridges, September 1, 1982.
148
13. Epps, J. A., Meyer, A. H. Larrimore, I. E., lJr., and lJones, H. L. "Roadway Maintenance Evaluation User's Manual", Texas Transportation Institute Research Report 151-2, September, 1974.
14. Epps, J. A. Larrirrore, I. E., Jr., Meyer, A. H., Cox, s. G., Jr., Evans, ,J. R., Jones, H. L., Mahoney, J., \4rotan, c. v., and Lytton, R. L., "The ~velopnent of Maintenance Management 'Ibols for Use by · the Texas State Department of Highways and Public Transportation", Texas Transportation Institute Research Report 151-4F, September, 1976.
15. Corlew, J. s., and Dickson, P. F., "Methods of Calculating Temperature Profiles of Hot-Mix Asphalt Concrete as Related to the Construction of Asphalt Pavements", Association of Asphalt Paving Technologists, Volume 37, p. 101, 1968.
16. Annual Rook of AS'IM Standards, 1984, Section 4, Volume 04.03, "Standard Test Method for Ductility of Bituminous Materials", Designation D113-79.
17. Anderson, D. I.,. Wiley, M. L., "Force-Ductility An Asphalt Performance Indicator", AAPr, Vol. 45, 1976.
18. Krchma, L. C., "Asphalt Consistency Control and Characterization by Flow Temperature", AAPI' Volume 36, 1967.
19. Annual Book of ~STM Standards, 1984, Section 4 , Volume 04.04, "Standard Test Method for Softening R>int of Bitumen (Ring and Ball Apparatus)", Designation D36-76.
20. RheqlQQY, Th.eoa and OOPliC.Cli5ions vcr~, 1, edited by Eirich, Frederick R. , Chapter 14, "Viscosity of Collo1dal Suspensions and Macromolecular Solutions", Frisch, H. L. and Simha, Robert, pp. 599-601, Academic Press, 1956.
21. Anderson, v. L., and McLean, R. A., ~~~gn q} Ex~riments.,: •• .} ~~liS:,t_ic .ffl?J?roac..,h, Marcel Dekker, Inc., 1974.
22. Annual Rook of .ASTM Standards, 1984, Section R, Volume 08.03, "Standard Test Method for Molecular Weiqht Distribution of Certain Polymers by Liquid Size-Exclusion Chromatography (Gel Perrreation Chromatography, GR::) , Designation D3593.
23. Soil Interpretation Records of F..dward I. Janak, lJr., Soil Scientist, Soil Conservation Service, from personal correspondence, Corsicana, Texas, December, 1983.
149
24. Annual Book of ASTM Standards, 19R3, Section 9, Volume 09.01, "Standard Methods for Rubber Products-chemical Analysis", Designation D297-81.
25. Annual Book of ASTM Standards, 1984, Section 4, Volume 04.03, "Standard Method of Test for Specific Gravity of Rituminous Materials, Asphalt Cements, and Soft Tar Pitches, by Pycnometer Method", Desl.qnation D70.
26. Epps, J. A., Gallaway, B. M., and Hughes, G. H., "Field .Manual on Design and Construction of Seal Coats", Research Report 214-25, Texas Transportation tnsti.tute, July 1981.
150
ADDITIONAL REFERENCES
1. Bernard, D. .A.. , "Federal Highway Administration Programs with Asphalt-Rubber", paper presented at Asphalt-Rubber, User-Producer Workshop, May 7-8, 1980.
2. Vedros, P., "Corps of Engineers F.xperience With Asphalt-Rubber", paper presented at Asphalt-Rubber, User-Producer Workshop, May 7-8, 1980.
3. Morris, G. R., "Arizona Department of Transportation Research and Developnent", paper presented at Asphalt-Rubber, User-Producer Wbrkshop, May 7-8, 1980.
4. Heinman, G., "Saskatchewan Experience With Asphalt-Rubber Binders", paper presented at Asphalt-Rubber, User-Producer WJrkshop, May 7-8 , 1980.
s. Piggott, M. R., f'.,eorge, :r. D. and ~Tood.hams, R. T., "'Ibronto Experience With Rubber-Asphalts", paper presented at Asphalt-Rubber, User-Producer Workshop, May 7-8, 1980.
6. Salam, Y. Ch~acteriz?tion of ~fopm?tion and Frfcture of ~phalt <~,.ODFre~tY• Institute of Transportation and Traff1c Engineering Series No. 1971:1, University of California, Berkeley, January 1971.
7. Majidzadeh, K., Buranarom, c. and Karakouzian, M. ARJ?lica!=-}pn .9! Ft;actur;e Mecl}pnj.cs fqr_)mproved Desi!;n, of Bit}-IDlinous Cof2~e. Vols. I and II. u. s. Federal Highway Adm1n1stration Reports FHWA-RD-76-91 and 92. u. s. Department of Transportation, Washington, D. c., June, 1976.
R. Chang,· H. s., Lytton, R. L., and Carpenter, s. H., Prediction of 1ttennal ~eflect_ion <:;rgyking iry ~Texas. Texas Transportat1on Institute. Research Report 18-3, Study 2-8-73-18, March, 1976.
9. Germann, F'. P., and R. L. Lytton, ~Y.,thooo}.~ for Pre;qi,cting tp~ Reflection 9rackiryg Life 9J .. Asphalt Concre~~.9yerrlay;s, Research Report No. 207-5, Texas Transportation Institute, March, 1979.
10. Ramsamooi, D. v., "Prediction of Reflection Crackinq in Pavement Overlays", Highway Research Board, Highway Researcry 'Re;cord .1}_4, Washington, D. c., 1973.
151
11. Luther, M. w., Maiidzadeh, K., and Chang, c. w., "JI.1echanistic Investigation of Reflection Cracki_nq of Asphalt Overlays", Transportation Research Board, Transpertation Research Record 572, National Research Council, ~7ashington, D.c., 1976.
12. Coetzee, T\1. F' •. , and c. L. Monisrnith, "Analytical Study of Minimization of Reflection Cracking in Asphalt Concrete Overlays by Use of a Rubber Asphalt Interlayer". Transportation Research Board, 1t,anspgr-tation ~~~~arch a~sord 700, Washington, D. C., 1979, PP• 100-108.
13. Maiidzadeh, K., and Sucharieh, G. !PerStu~ of P~yement Overlqy ~~.J.gn: ..... Fin.q}-..J3epgr.t. Ohio State Un1vers1ty, Columbus, 1977.
14. Treybig, H. J., McCullough, B. F., Smith, P. ~ and Von Quintus, H. ov~rlax Desigr.~~n9 Ref~ect;ion ~t,:ackipg .f\I)alysis f.o:r;, R?;giQ. ,Pftvcrment~. Vol. 1 and 2. u. s. Federal Highway Administration Report No's. FHWA-RD-77-66 and 67, 1977.
15. Coetzee, N. F., and c. L. Monismith. "Considerations in the Design of Overlay Pavement to Minimize Reflection Cracking", Pfs>s~ef\fDgs, Third Conference on Asphalt Pavements for Southern Africa, Durban, South Africa, 1979, pp. 290-302.
16. Epps, J. A., M.eyer, A. H., Larritrore, I. E. and \Jones~ H. L., "Roadway Maintenance Evaluation User's Manual", Research Report 151-2, Texas Transportation Institute, September, 1974.
17. Way, G. B., "Prevention of Reflective Cracking Minnetonka,.;.East, .Appendix R (1979 Addendum Report), August, 1979.
lR. Epps, \.J. A., Gallaway, B. M., and Hughes, G. H., "Field Manual on Design and Construction of Seal Coats", Research Re-port 214-25, Texas Transportation Institute, July 1981.
19. Epps, J. A., and \'\botan, c. v., "Airport Pavement Recycling Economics", report prepared for u.s. Navy, August 1981.
20. Lottman, R. P. "Predicting Moisture Induced Damage Asphalt Concrete", TRR - 515.
21. Schmidt, R. J. , "A Practical Methoo for Measuring the Resilient Modulus of Asphalt-Treated Mixes", HRR No. 404, HRB, 1972, pp. 22-32.
22. Lansdon, H. G., "Construction Techniques of Placement of A.sphal t-Rubber Membranes" , Report 104, Arizona Department of Transportation, paper presented at Thirteenth Pavinq Conference, University of New Mexico, \January, 1976.
152
23. Way, G. R., "Prevention of Reflection Cracking in Arizona Minnetonka-East (A Case Study)", Arizona Department of Transportation, May 1976.
24. Ford, w. o. and Lansdon, H. G., "Development and Construction of Asphalt Rubber Stress Absorbing Membrane", Report lOB, Arizona Department of Transportation, paper presented at 55th Annual Conference of WASHTO, June, 197n.
25. Lansdon, H. G., "'Ihe Blending of Granulated Rubber and Asphalt for Use of a Crack Sealant", Report lOHA, Arizona Department of Transportation, July, 1976.
26. Green, E. and 'Iblonen, w. J., "'Ihe Chemical and Physical Properties of Asphalt-Rubber Mixtures", Report AOOT-RS-14(162), Arizona Department of Transportation, July, 1977.
27. Frobel, R. K., Jimenez, R. A. and Cluff, c. R., "Laboratory and Field Developnent of Asphalt-Rubber for Use as a Waterproof J1.1embrane", Report AOOT-RS-14(167), Arizona Department of Transportation, J"uly, 1977.
28. Jimenez, R. A., "Testing Methods for Asphalt-Rubber", Report AOOT-RS-15(164), Arizona Department of Transportation, January, 1978.
29. Forstie, D., Walsh, H. ano Way, G., "Membrane Technique for Control of Expansive Clays", Rel;X)rt 1?.5, Arizona Department of Transportation, paper presented at 5Rth Annual TRB Meeting ,January, 1979.
30. Way, G. B., "Prevention of Reflective Cracking Minnetonka-East (1979 Addendum Report)", Report AOOT-RS-15 ( 130), Arizona Department of Transportation, August, 1.979.
31. Jimenez, R •. A., "Design of Asphalt-Rubber and Aggregate Mixtures", Report AfX)T-RS-15 ( 131) , Arizona Department of Transr.x>rtation, October, 1979.
32. Pavlovich, R. n., Schuler, T. s., and Rosner, J. n., "Chemical and Physical Properties of Asphalt-Rubber", Report AOOT-:RS-15(133), Arizona Department of Transportation, November, 1979.
33. Gonsalvas, G. F. D., "Evaluation of Road Surfaces Utilizing Asphalt-Rubber-1978", Report Number 1979-GG3, Arizona nepartrnent of Transportation, November, 1979.
153
34. Morris, G. R. and Mclbnald, c. H., "Asphalt-'Rubber Membranes Development, Use and Potential", Record 595, Transportation Research Board, 1975.
35. Mclbnald, c. H., 11Asphalt-Rubber Canpounds and 'Their Applications for Pavement", 21st California Streets and Highway Conference, January, 1969.
36. McDonald, c. H., "An Elastomer Solution for 'Alligator' Pattern, or Fatigue, Cracking in Asphalt Pavements", International Symposium on the Use of Rubber in Asphalt Pavements, May, 1971.
37. · Mclbnald, c. H., "Rubberized Asphalt Pavements", paper presented at 5Rth Annual Meeting of AASHTO, 1972.
38. Stokely, J. A. and Mclbnald, c. H., "Hot Asphalt-Rubber Seal Coats to Cure Cracking Streets", Public Wbrks, July, 1972.
39. McDonald, c. H., "Final Report on Asphalt-Rubber Special Test Section Placed January, 1970 on 19th Avenue", Enqineering Division, City of Phoenix, Arizona.
40. MciX:mald, c. H., 11Bituminous Paving as Related to Large COl'l:l'rercial Airports in the Urban Environment", presented at Annual Meetinq of Highway Research Roard, 1972.
41. Morris, G. and Mclbnald, c. H., "Asphalt-Rubber Stress Absorbing Membranes-Field Performance and State-of-the Art.
42. Schnormeier, R. H., "Use of Asphalt Rubber on Low-Cost, IDw Volume Streets", Special Report 160, Transportation Research Board.
43. Schnormeier, R. H., "Eleven-Year Pavement Condition History of Asphalt Rubber Seals in Phoenix, Arizona", City of Phoenix, 1979.
44. McDonald, c. H., u. s. Patent 4018730.
45. Mcibnald, c. H., u. s. Patent 4069182, Llanuary, 17, 197R.
46. Morris, G. R. and Mclbnald, C. H., "Asphalt-Rubber Stress Absorbing Membranes", presented at Annual Meeting of Transportation Research Board, 1976.
47. "Application of a Hot Asphalt-Rubber Underseal OVer ACP Prior to Overlay- IH 10, Kimble County", Exper~ental Proiect Report 606-6, Texas State Department of Highway and Public Transportation, ~January, 1980.
154
48. Clark, w. H., "Restorative Highway Maintenance Techniques", paper presented to 19th Annual Asphalt Paving Conference, Troy, New York, New York State Thruway Authority, March, 1979.
49. "Project Status Report", Demonstration Proiect No. 37, Discarded Tires in Highway Construction, Federal Highway Administration, Region 15, July, 1978.
50. "Project Status Report", nemonstration Project f\Jo. 37, Discarded '-
Tires in Highway Construction, Federal Highway Administration, Region 15, September, 1979.
51. Hankins, K. D. and Nixon, J. F., "Experimental Seal Coat Construction, Including Overflex-Two Year Analysis:, Report FHWA-EP-37-1, Federal Highway Administration, March, 1979.
52. Donnelly, D. E. and Swanson, H. N., "Reflection Cracking, Crumb Rubber Derronstration, Kannah Creek, Colorado", Report FHWA-DP-37-2, Federal Highway Administration, September, 1979.
53. Stewart, J. , "Seal Coat Construction at Rocky, Oklahoma, Using Asphalt Rubber as the Binder", Report FHWA-DP-37-3, Federal Highway Administration, September, 1979.
54. "Use of Granulated Rubber from Discarded Tires in Seal Coat Construction, Sioux Falls, South Dakota", Report FHWA-DP-37-4, Federal Highway Administration, September, 1979.
55. "Asphalt-Rubber Used as an Interlayer - Jamestown, North Dakota", Report FHWA-DP-37-5, Federal Highway Administration, October, 1979.
56. Herendeen, H., "Evaluation of Stress Absorbing Merrbrane Interlayer ( SAMI) in Idaho", Report FHWA-DP-37-6, Federal Hiqhway Administration, October, 1979.
57. Jackson, N. c., "Rubber-Asphalt Rinder Stress-Absorbing Membrane Interlayer - Moses Lake, Washington", Report FHWA-DP-37-7, Federal
-Hiqhway Administration, November, 1979.
58.- Strong, M. P., "'Ihe Evaluation of Rubber Asphalt Surface "'Treatment in Preventing Fatigue Crack Reflection in Bituminous Overlay Construction- Haywood County, North Carolina", Report F'HWA-DP-37-10, Federal Highway Administration, January, 1980.
59. Vedros, P. lJ., Jr., "Evaluation of the Effectiveness of Membranes for Prevention of Crack Reflection in 'Ihin Over layer", Interim Re[X)rt, Miscellaneous Paper GL-79-4, u. s. Army Engineer Waterways Experiment Station, Vicksburg, Mississippi.
155
61. Shuler, T. s., Hamberg, D. J. "A Rational Investigation of Asphalt-Rubber Properties", Unpublished Report University of New Mexico Engineering Research Institute, August, 1981.
62. Brownie, R. R., "Evaluation of Rubber-Asphalt Binder for Seal Coatinq Asphaltic Concrete, March, 1974- June, 1976", TM-No. M-53-76-5, Naval Civil Engineering Laboratory, Fort Hueneme, California, August, 1976.
63. Brownie, R. 'R. , "Evaluation of Rubber-Asphalt Binder for Seal Coating Asphaltic Concrete, NP1'R El Centro, California, March, 1974 - Lluly, 1977", TM-No. M-53-77-3, Naval Engineering Laboratory, Fore Hueneme, California, August, 1977.
64. McLaughlin, A. L., "Reflection Cracking of Bituminous OVerlays for Airport Pavements; a State of the Art", Report No. FAA-:RD-79-57, Federal Aviation Administration, May, 1979.
65. Deese, P. L., et al., "200 ,000,000 Tires per year: Options for Resource Recovery and Disposal:, Vol. 1, report prepared by Urban . Systems Research and Engineering, Inc., for Environmental Protection Agency, November, 1979.
66. westerman, R. R., "Tires: Decreasing Solid Wastes and Manufacturing 'Throughout-Markets, Profits and Resource Recovery", Report No. EPA-600/5-78-009, Environmental Protection Agency, July, 1978.
67. Heiman, G. H., "Pavement Management System - Pavement Monitoring and Decision Criteria", paper presented to workshop on Pavement Management, Saskatchewan Department of Highways and Transportation, November, 1977.
68. Scott, J. L. M., "Use of Rubber .A..qphalt Binder With Graded Aggregate for Seal Coats", Technical Report 28, Saskatchewan Highways and Transportation, January, 1979.
69. Scott, J. L. M., "Use of Rubber Asphalt Binder With Graded Aqgregate for Seal Coats", Report BPS 4-NW-79-1, Environment Canada, Saskatchewan Highway and Transportation, September, 1979.
70. Piggott, M. R. Redelmeier, R., Silgardo, B. and ~hams, R. T., "'Ihe Toughening of Asphalt by Rubber", University of 'Ibronto, 1977.
156
71. Piggott, M. R., Ha<iiis, N. and v;bodhams, R. T., "Improved .a.sphalts for Low Temperature Use", University of Toronto, 1977.
72. Piggott, M. R., Ng, W., George, J. n. and l~'OOdharns, 'R. T., "Improved Hot Mix Asphalts Containing Reclaimed Rubber", Procee<iinos, AAPr, Vol. 46, 1977.
73. Piggott, M. R., Davidson, T., Chili, D. and Vbodhams, R. T., "The Effect of Unvulcanized Rubber Waste on the 'Ibughness of .l'\sphal t Cement", University of Toronto, 1978.
74. Piggott, M. R., Fu, B. and W::>odhams, R. T., "An Evaluation of Chevron SS-1 Tack Coat Materials for Rubberized Asphalt Concrete", University of Toronto, 1978.
75. Piggott, M. R. and WJodhams, R. T., "Recycling of Rubber Tires in Asphalt Paving Materials", Report prepared for Environment Canada, University of Tbronto, March, 1979.
7 6. Shim-'Ibn, '-1. , Kennedy, K. A. , Piggott, M. R. and Vbodhams, R. T. , "Low Temperature Dynamic Properties of Bitt.nnen-Rubber Mixtures", University of Tbronto, December, 1979.
77. Piggott, M. R., Ciplijauskas, L• and W:x>dham..s, R. T., "Chemically Modified Asphalts for Improved wet Strenqth Retention, University of Toronto, 1979.
78 •. Piggott, M. R. Shim Ton, l1. and W:x>dhams, R. T., "Viscoelastic Behavior of Rubber Modified Asphalt Near the Brittle Fbint", University of Toronto, 1979.
79. McDougal, ,J. I., "Merrorandum to H. J. From on Rubberized Asphalt Concrete", November, 1979.
80. Oliver, '-1. w. H., "A Critical Review of the Use of Rubbers and R:>lymers in Bitumen Bound Paving Materials", Interim Report AIR-1037-1, Australian Research Board, 1977.
81. Bethune, lJ. D., "Bittuninous Surfacing Developnents", Report on Overseas Mission to Study, County Roads Board, Victoria, Australia, 1977.
82. Thompson, P. D. and Szathowski, w. s., "Full Scale Road Experiments Using Rubberized Surfacinq Materials", RRL Report LR 370, Road Research Laboratory, 1970.
83. Geoffray, research in progress at French Ministry of F4Uipment for Regional Planning, Paris, France.
157
84. Chehovits, J. G., Dunning, R. L., Morris, G.T., "Characteristics of Asphalt-Rubber by the Sliding Plate Microviscometer", Report to be published by Arizona Deparbment of Transportation.
85. Schweyer, H. E., Burns, A. M., "Low Temperature Rheology of Asphalt Cements. III. Generalized Stiffness - Temperature Relations of Different· Asphalts", AAPI', Vol. 47, 1978.
86. Jimenez, R. A., ''Testing Asphalt-Rubber with the Schweyer Rheometer", NSF Report ATTI-R0-1, University of Arizona, January, 1980. ·
87. Jimenez, R. A., "Laboratory and Field Developnent of Asphalt-Rubber For Use as a Waterproof Membrane'', AOOT ReJX)rt :RS-14 ( 167), A.rizona Department of Transportation,! July 1977.
88. LaGrone, B. D. and Huff, B. J. , "Use of Waste Rubber in Asphalt Paving", paper presented at the Colorado State University Asphalt Paving Seminar, Fort Collins, Colorado, 1973.
R9. LaGrone, B. n. and Huff, B. ,J., "Utilization of Waste Rubber to Improve Highway Performance and Durability", paper presented at 52nd Annual Meeting, Highway Research Board, ,January, 1973.
90. Huff, B. ,J., "Rubber in Asphalt Pavements, A Method of Utilizinq All of Our "Rubber Waste", paper prepared for presentation to American Chemical Society, u. s. Rubber Reclaimi-nq, 1977.
91. "Field Audit of ARM-R-SHIELD Surface Treatments on Van Buren Road, City of Phoenix, Arizona", Technical Report ARS-501, Arizona Refinery Company, December, 1977.
92. Ham, W. D., "ARM-R-SHIELD Stripping Procedure", Report PROD. 78-38R, Union Oil Company Internal Report, September, 1978.
93. "Design Method for A'RM-R-SHIEID Surface Treabnent", n-301 (tentative), Arizona Refinery Company, 1979.
94. Nielsen, D. L. and Baqley, ,J. R., "Rubberized Asphalt Paving Composition and Use Thereof", United States Patent 4,068,023, January 10, 1978.
95. Coetzee, N. F. and Monismith, c. L., "An Analytical Study of the Applicability of a Rubber-Asphalt Membrane to Minimize Reflection Cracking in Asphalt Concrete Overlay Pavements", University of California, Berkeley, California, June, 1978.
96. Huff, B. ,J. and Vall erg a, B. A. , "Characteristics and Performance of Asphalt-Rubber Material Containing a Blend of Reclaim and Crumb Rubber",. paper presented at 58th Annual Meeting of Transportation Research Roard, Arizona Refinerv Company, ,January, 1979.
158
97. Vallerga, B. A. and Baglev, J. R., "Design of Asphalt-Rubber Single Surface Treatments with Multi-Layered Aqqreqate Structures", paper presentoo at A..S'IM Symposium at San Diego, California, Arizona Refinery Company, December, 1979.
98. "Specification for ARM-R-SHIELD", Spec. M-101-80, Arizona Refinery Company, 1980.
99. "Construction Specifications for ARM-R-SHIELD Surface Treatment", Spec. JC-201-RO, Arizona Refinery Company, 1980.
100. "Construction Specification for ARM-R-SHIELD Stress Absorbing Membrane Interlayer", Spec. C-202-80, Arizona Refinery Company, 1980.
101. "Specifications for ARM-R-SHIELD-CF", Arizona Refinery Company.
102. "ARM-R-SHIELD", Arizona Refinery Company.
103. "Estimated Cost Comparisons - ARM-R-SHIELD SAMI's Vs. Other Asphalt Hot-Mix Overlays", Arizona Refinery Company, 1(}80.
104. "Stress-Absorbing Membrane (SAM)", Sahuaro Petroleum and Asphalt Company, January, 1977.
105. "Stress-Absorbing Membrane (Interlayer)", Sahuaro Petroleum Asphalt Company, January 1, 1977.
106. "Stress-Absorbing Membrane (Interlayer) (Use with ACFC)", Sahuaro Petroleum Aspha1 t Company, January 1 , 1977.
107. "Crack-Sealing Specifications for Sealinq Cracks in "OCCP and AC", Sahuaro Petroleum Asphalt Company, ,January 1, 1977.
108. Pavlovich, R. D., "Laboratory Evaluation Procedures for Asphalt-Rubber", presented to TRB Comnittee A.2001, ,January, 1979.
109. Pavlovich, R. D. and Shuler, T. s., "Laboratory Measurement of Physical Properties of Asphalt-Rubber", New Mexico Paving Conference, January, 1979.
111. Stephens, Jack E. and Mokrewski, s. A., "The Effect of Reclaimed Rubber on Bituminous Paving Mixtures", University of Connecticut, March, 1974.
112. Gallaway, B. M. and LaGrone, R. D., "Use of Rubber Aggregate in a Strain Relieving Interlayer for Arresting Reflection Cracks in Pavements", International Symposium on the Use of Rubber in Asphalt Pavements, 1971.
113. Bushey, R. w., "Experimental Overlays to Minimize Reflection Cracking", Interim Report FHWA-cA-TL-3167-76-28, California Department of Transportation, September, 1976.
159
114. Donnelly, n. E., McCabe, P. J. and Swanson, H. N., "Reflection Cracking in Bituminous Overlays", Report No. COOH-P&R-R-76-6, Colorado Division of Highways, December, 1976.
115. Jimenez, J'R. A., Morris, G. R., DaDeppo, D. A., "Tests for a Strain-Attenuating Asphaltic Material", MPI', Vol. 48, 1979.
116. Oliver, J. w. H., "Research on Asphalt-Rubher at the Australian Road Research Roar<i", Presented at the National Seminar on Asphalt-Rubber, F~~ Demonstration Projects Division, October, 1981.
117. "Chemical and Physical Properties of Asphalt-Rubber, Phase II, Vol. IVB, AOOT HPR, 1-19 (159), Report in preparation.
160
A.PPENDIX A
Photolog Summary - El Paso
161
~ Table ~ to-~ ~/ ~~·
"~ ~ 0· ()'
J't ~ A'.
Slight A~ ~
1o J'J' l' ~~ F* N**
Transv .• ft. 27 106
Long.~ ft. 9 59
. 2 A 11 i g., ft. 358
Flushing, ft~
Pat~hing, ft~
Pumping, ft.
~ Table
...<J· to-~.., .1/. ~"
<?~. ~0' -..;..,
~
A'. J't A ~
1o Slight ~S' J' l'
~~ F N
Transv., ft. 94 78
Long., ft. 134 23
Allig., ft. 2 86
Flushing, ft~ 362
I')
Patching, ft~
Pumping, ft.
*Filled cracks. **Not-filled cracks. 162
Al • Photo log 1 .
Moderate Severe
F N F N
6 21 74
33 11 10
322 5)
A2 . Photo log 2 •.
Moderate Severe
F N F N
' 83 22 240
4
90 4
~ Table A3. Photo log 3. ~· too~;,
.I.; "t <?.,.
<9<7 i.J.. , J't ,.<:'-,
Slight Moderate Severe , ;,<9 4o \S'J' t-,4' F N F N F N
Transv .• ft. 155 130 90 3 4 196
Long., ft. 80 27
Allig., ft. 2 8 10
Flushing, ft~ 793
Patching, ft~
Pumping, ft.
~ Table A4 . Photol og 4 .
~· t.-<9;, ..
.I.; "t <?).
<9<7 ;._~, , J't ,.<:'-.
;,<9 ~
4o Slight Moderate Severe \S'J' {<
~
4' F N F N F N
Transv., ft. 112 16 332 41 72 194
Long., ft. 36 56 47 9 30
A 11 i g. , ft. 2 278 129
Flushing, ft~
Patching, ft~ 806
Pumping, ft.
163
~ Table AS. Photolog 5 . ~· t-{OA
-'-~. 'l< ~-
{00' ~ ~
~. J'(" Slight Moderate Severe A~ ~
1o irs " ~+ F N F N F N
Transv., ft. 265 8 52 11
Long., ft. 56 11
Allig., ft. 2 15
Flushing, ft~ 494
Patching, ft~
Pumping, ft.
Table A6 . Photolog 6 . ~
~· t.-(QA
-'-~. 'l< ~ .....
(QO' ~ ~
~ s""' ~· Moderate Severe ~J' 1o Slight
J' " .. + F N F N F N
Transv., ft. 195 155
Long., ft. 89 21
Allig., ft. 2 31
Flushing, ft~ 197
Patching, ft~
Pumping, ft.
164
& Table A7. Photo log 7 . ~~-
~· (Q.h
.1.1. "~ ~·
(QQ" i.J,
.. ,(' . ..rt .. Slight Moderate Severe A 16 (Q..r ..r ~
.. 4' F N F N F N
Transv.t ft. 203 107 20 60
Long., ft. 61 31 2
. 2 Allig., ft. 1149 232
Flushing, ft~ 1120
Patching, ft~ 378 318
Pumping, ft.
~ Table A8 . Photolog 8 .
~· t--(QA .1.1. )~
~· (QQ" i.J, ..
,('. J't A ..
Slight Moderate Severe (Q..r 16 ..r ~
.. 4' F N F N F N
Transv., ft. 235 125 103 35
Long., ft. 29 52 2
Allig., ft. 2 763 91
Flushing, ft~ 667 27
Patching, ft~
Pumping, ft.
165
~ Table A9. Photo log 9 . ~· t.-~A
/.1. )~
~· ~Q' ;.J,
~,;('-
J'"' ~· Slight Moderate Severe A (C) ~· J"J' ot
~~ F N F N F N
Transv., ft. 301 106 20 9
Long., ft. 49 35
Allig., ft. 2 84
Flushing, ft~ 260
Patching, ft~ 378
Pumping, ft.
~ Table A10. Photo 1 og 10 .
~· J..(C)A /.1. )l<
<?). ~Q' ;.J, ..
,;('-. J't A (C)
~
4[, Slight Moderate Severe J'J' t-
~~ F N F N F N
Transv., ft. 76 128 287 4 21 43
Long., ft. 109 69 84 8 31
Allig., ft. 2 178 704 496
Flushing, ft~ 422 46 35 '1
Patching, ft~ 624
Pumping, ft.
166
~ Table All. Photologii. ~· t-(Qh //. ltc
~· (QO"' ;.;,
J'l' ~ ..<'.
Slight Moderate Severe h(Q ~
1o J'J' (!< ~~ F N F N F N
Transv ... ft. 137 174 61 79
Long., ft. 37
Allig., ft. 2
Flushing, ft~
Patching, ft~
Pumping, ft.
~ Table A12. Photol og 12 .
~· t-(Qh
//. "ic ~·
(QO"' ;.;, ~
..<'. J'l' h(Q
~
1o Slight Moderate Severe J'J' (!<
~~ F N F N F N
Transv., ft. 70 76 112 39 4 24
. Long., ft. 35 10 68 4 2
Allig., ft. 2 255 218 ??'-1
Flushing, ft~ 584 202
Patching, ft~ 200
Pumping, ft.
167
~ Table A13. Photolog 13. ~· J...~;,
.1.1. "t ~·
~0' ;.;,.. ~~
st< ~· 1!.· Slight Moderate Severe ;,(C)
ss ot< ~4' F N F N F N
Transv .• ft. 143 45 eo 19 31
Long., ft. 102 13 11 4
Allig., ft. 2 302 363 113
Flushing, ft~ 333
Patching, ft~ 419 40
Pumping, ft.
~ Table A14. Photolog 14.
~· J...(Q;, .1.1. "t
~,. (QO' ;.;,..
~
~ st< ;, ~· (QJ' 4o Slight Moderate Severe
s {' ~4' F N F N F N
Transv., ft. 202 157 89
Long., ft. 119 23 9 5
Alliq., ft. 2 213 403 25
Flushing, ft~ 268
Patching, ft~
Pumping, ft.
168
~ Table A15. Photolog 15. ~· t..~~
.1/. "tc <?_,.
~()' ;,J... , ,f:'o. J'"~ ,
11. Slight Moderate Severe ~J'
J' <:)" ,~ F N F N F N
Transv., ft. 394 31 60
Long., ft. 286 37 30
A 11 i g ., ft . 2 744 136
Flushing, ft~ 342
Patching, ft~ 963
Pumping, ft.
& Tab1 e A16. Photo 1 og 16 .
~ ~k "/ (0~.,. ~ ~
<?_,. 0' , J' ,f:'o.
"~ ,
Slight Moderate Severe ~J' 1o J' '{' ,~
F N F N F N
Transv., ft. 112 93 110 6
Long., ft. 67 14 38
Allig_., ft. 2 122 779 194
Flushing, ft~ 260 14 ')
Patching, ft~ 820 725
Pumping, ft.
169
~ Table A17. Photolog 17. ~ t.-(9 "/ ..... ,. ~ (J,
<?,. 0' .# ...<'.
J'" ~ Slight Moderate Severe ,(9
'*' J'J' ol' .#4' F N F N F N
Transv., ft. 153 187 37 6
Long., ft. 134 17
Allig., ft. 2 542 188
Flushing, ft~ 175
Patching, ft~ 428 212
P~mping, ft.
~ Table A18 Photo 1 og 18 .
~ t.-(9 "/ ..... ,. ~ ~
~· 0' ~
...<'. J'(< ,(9
~
16 Slight Moderate Severe J'J' '{'
~
4' F N F N F N
Transv., ft. 109 74 169 31
Long., ft. 76 35 87
Allig., ft. 2 331 149
Flushing, ft~ 1039 .,
Patching, ft': 127 134
Pumping, ft.
170
~ Table A19. Photolog 19~ ,.(" t.-~ ~/ :A~,
~ ~ <?~. 0'
., ,.(". sec ., s 1 i.ght Moderate Severe A~ 1o SS' '(< ., 1-- F N F N F N
Transv., ft. iO 86 179 8
Long., ft. 184 30 153 7
Allig., ft. 2 71 38
Flushing, ft~ 1219 119
Patching, ft~ 335 109
Pumping, ft.
Table A20 . Photolog 20. ~
,.(" t.-~ ~/ A~. /~ ~-
<?~. 0' ., ,.(". S't
A _,
1o Slight Moderate Severe (QS' S' t-
"'1-- F N F N F N
Transv., ft. 200 26 25
Long., ft. 283 11 8
A 11 i g. , ft. 2 2
Flushing, ft~ 242
Patching, ft~ 155 265
Pumping, ft.
171
~ Table A21. Photolog 21. ~ :e.-(0 ~/ ~~· ~ ~
~- 0' ., ~ J'c:" .~· . Slight Moderate Severe ;,~ 16 J'J' to
.,4' F N F N F N
Transv.~ ft. 191 155 13
Long., ft. 103 18
Allig., ft. 2 447
Flushing, ft~ 261
Patching, ft~ 683
Pumping, ft.
~ Table A22. Photolog 22.
~ :e.-~ ,)/ ~~· /~ ~
<?~. 0' ., J't;,
..<' .~· Moderate Severe ~J' 4o Slight
J' to .,4' F N F N F N
Transv., ft. 274 71 14
Long., ft. 80 5
A 11 i q • , ft . 2 134
Flushing, ft~ 219
Patching, ft~ 70 72
Pumping, ft.
172
~ .Table A23. Photolog 23. ~· t..(Q~
/.1. 'tc <?,.
(QO" ~ .#
J'('C ,~('-. Slight Moderate Severe ~(Q
.#
1G SJ' 'l' .#
4' F N F N F N
Transv. .. ft. 131 68 57 4
Long., ft. 26 7
Allig., ft. 2 130
Flushing, ft~ 1028
Patching, ft~
Pumping, ft.
Table A24 . Photo log 24. ~
~· t.-(Q~ .1.1. "~
<?,. (QO" ;~
.#
J'~ ,~('-. ~ .#
1o Slight Moderate Severe (QJ' J' 'l'
.#+ F N F N F N
Transv., ft. 145 2 4
Long., ft. 32 11
Allig., ft. 2 333
Flushing, ft~ 372 I)
Patching, ft: 178 140
Pumping, ft.
173
~ Table A25. Photolog 25. ~· t.-(Q~
.1.1. 't 0·
~0' ~ ~
~ ..rt< ~· Slight Moderate Severe ~(Q ~· .S..r ot
~4' F N F N F N
Transv .• ft. 81 49 117 17 14
Long., ft. 38 30 10
Allig., ft. 2 213 59
Flushing, ft~ 578
Patching, ft~
Pumping, ft.
Table A26 Photo log 26. ~
")· t--~~ //. 't
<?,. ~0' ~
~
~ . ..rt ~ ..
4o Slight Moderate Severe ~..r ..r t-.. 4'
F N F N F N
Transv., ft. 224 16 5
Long., ft. 326 10 129 18 14
Alliq., ft. 2 458 197
Flushing, ft~ 301
Patching, ft~ 11 680
Pumping, ft.
174
~ Table A27. Photo log 27. ~· t.-(Q;,
.1.1. ~~
~· (QQ' ~ .#~
J'c:< .#. Sl i·ght Moderate Severe ;,(Q 1o J'._r (.< .#4' F N F N F N
302 78 64 4 51 Transv.!l ft.
Long., ft. 282 36 19
Allig., ft. 2 314 57
Flushing, ft~ 1021 15
Patching, ft~ 323 385
Pumping, ft.
~ Table A2f} Photolog 28.
~· t.-(QA
.1.1. "~ <?,. (QQ' "J; ,
~. J't A(Q
, 4o Slight Moderate Severe
J'J' (.<
"4' F N F N F N
Transv., ft. 24 18 54 12 12
Long., ft. 304 128
Allig., ft. 2 185 75
Flushing, ft~ 1274 540
Patching, ft~ 30 120
Pumping, ft.
175
APPENDIX B
Photolog Sunmary - Buffalo and Brownsville
176
~ Table 81. Photo log 1 . ~· J...{Q;, /~ "tc
~· {QO' ;_~,. .. ~ . .r(C Slight Moderate Severe ;, .#
1o ~.r .r 't'
.. 4' F N F N F N
Transv ... ft. 1912 192
Long., ft.
Allig., ft. 2
Flushing, ft~
Patching, ft~
Pumping, ft.
~ Table 82. Photol og 2 .
~ J...{Q "/ ..,.,_,. ~ ~
~· 0' ~
~ .r(C .#. ;,
1o Slight Moderate Severe {Q.r .r {'
.. 4' F N F N F N
Transv., ft. 1954 63
Long., ft.
A 11 i Q. , ft. 2
Flushing, ft~ ,
Patching, ft:
Pumping, ft.
177
~ Table 83. Photo log 3 . ~- J..(Qh
/.1. )lc 0·
(QO" "J..
~ ~-J'l' . ~ Slight Moderate Severe h(Q 16 J'J' to
~~ F N F N F N
Transv .• ft. 1849 127
Long., ft.
Allig., ft. 2
Flushing, ft~
Patching, ft~
Pumping, ft.
Table 84 . Photo log 4. ~
~ b(Q )> '>· ~ ~
<?). 0' ~
~-J'(' h(Q
~
4o Slight Moderate Severe J'J'
"' ~~ F N F N F N
Transv., ft. 1819 41
Long., ft.
Alliq., ft. 2
Flushing, ft~ ~
Patching, ft:
Pumping, ft.
178
~ Table 85. Photo log 5. ~ t-{Q ~/ "~· "~ ~
<?~. 0' .# ~ . ..r(C , Slight Moderate Severe A~ 1o S'..r t-
.#""' F N F N F N
Transv .• ft. 793 5
Long., ft.
Allig., ft. 2
Flushing, ft~
Patching, ft~
Pumping, ft.
~ Table 86 . Photolog 6 .
~· t-{QA
/~ ""cc <?~.
{QO" :.J.. , ~ . ..rt
A , . ~..r 1o Slight Moderate Severe
..r t-,""' F N F N F N
Transv., ft. 775 17
Long., ft.
Alliq., ft. 2
Flushing, ft~ I')
Patching, ft7
Pumping, ft.
179
~ Table 87. Photo log 7 . ~· t.-(<).1-o
-'-~. "~ <?_,.
(QQ' ;k-
~ ~. J'~ ~ Slight Moderate Severe .1-o~ 16 J'J' t
~
/fr F N F N F N
Transv., ft. 1518 49
Long., ft.
Allig., ft. 2
Flushing, ft~
Patching, ft~
Pumping, ft.
Table 88 . Photo log 8. ~
~ t-~ "/ ;.c.,_,. /~ ~
0· 0' ~
~. J'~ A .J Moderate ~J' 16 Slight Severe
J' t ~-1' F N F N F N
Transv., ft. 1452 58
Long., ft.
Allig., ft. 2
Flushing, ft~ .,
Patching, ft~
Pumping, ft.
180
~ Table 89 . Photo log 9 . ~· ~~A
/.1. ~l<
<?~-~0" -..;, .,
J'"' ..<--. Slight Moderate A~
., ~·
Severe \.S"J' ott
.,~ F N F N F N
Transv .• ft. 575 37
Long., ft.
Allig., ft. 2
Flushing, ft~
Patching, ft~
Pumping, ft.
Table BlO Photo 1 og 10 . S'~
~· .t--~A /.1. ~"
<?~. ~0" -..;,
J'"' "..<--
A~ .,· ~ Slight Moderate Severe \.S"J' 0£<
.,~ F N F N F N
Transv., ft. 592 51
Long., ft.
Alliq., ft. 2
Flushing, ft~
Patching, ft~
Pumping, ft.
181
~ Table B 11. Photolog 11 . ~· ~~~
//. )~
0· ~Q' "J,.
.# ~. J't ., Slight Moderate Severe ~~ ~·
J'J' ot .#4' F N F N F N
Transv., ft. 1156 41
Long., ft.
Allig., ft. 2
Flushing, 2 ft.
Patching, ft~
Pumping, ft.
J& Table 812. Photo log 12·
~ J..(Q
"/ ""'.~· ~ ~
0· Q' .#
~. J't ~(0
., 4o Slight Moderate Severe
J'J' t .,4' F N F N F N
Transv., ft. 917 37
Long., ft.
A 11 i g. , ft. 2
Flushing, ft~ .,
Patching, ft~
Pumping, ft.
182
~ Table 813. Photolog 13. ~· t--~A
//. _,~
~-~0" "J.-
~
~. J'('C Slight A~ ~
* Moderate Severe
J'J' 0('<
~4' F N F N F N
Transv q ft. 997 95
Long., ft.
Allig., ft. 2
Flushing, ft~
Patching, ft~
Pumping, ft.
~ Table 814. Photo log 14.
~. t--(9 . -' / n_,.
~-~0" ~
~
~. J'('C A ~
4o Slight Moderate Severe (9J' J' l'
~4' F N F N F N
Transv. , ft. 1192 99
Long., ft.
Alliq., ft. 2
Flushing, ft~
Patching, ft~
Pumping, ft.
183
~ Table B15. Phofo 1 og 15 . ~- t.-~h
/.1. "lc <?_,.
~0' -..;.. ~
..rl' ,('-. Slight Moderate Severe .#
h~ ~ J'..r l' .#4' F N F N F N
Transv .• ft. 1092 180
Long., ft.
Allig., ft. 2
Flushing, 2 ft.
Patching, ft~
Pumping, ft.
~ Table B16. Photo 1 og 16 .
,('-. to-~ .I/ A_,. ~ ~
<?_,. 0' .#
..rt ,('-. .#
h(Q 1o Slight Moderate Severe J'..r l'
.#4' F N F N F N
Transv., ft. 1232 144
Long., ft.
A 11 i g. , ft. 2
Flushing, ft~
Patching, ft~
Pumping, ft.
184
~ Table 817· Photolog 17· ~· to-~~
.1~ 't <:::>,.
~0" -..J;. .. sec /:'.
Slight Moderate .. Severe ~~ 1o S'J' !" .. ~ F N F N F N
Transv., ft. 1339 55
Long., ft.
Allig., ft. 2
Flushing, ft~ ,,
Patching, ft~
Pumping, ft.
~ Table 818. Photo 1 og 18 .
/:' to-~ '/ '-,·
.1~ ~ <::>,. 0' ..
/:'. J't .. r. 1o Slight Moderate Severe (QJ'
J' !" .. ~ F N I F N F N
Transv., ft. 1257 33
Long., ft.
A 11 i g. , ft. 2
Flushing, ft~ I')
Patching, ft7
Pumping, ft.
185
~ Table 819. Photo log 19. "'-~· ~""'
.1.1. "t <?_,.
~0' :.;, ~
~. J't .. Slight Moderate Severe ""'~ 1o J"J' t-~4' F N F N F N
Transv .• ft. 1279 54
Long., ft.
Allig., ft. 2
Flushing, 2 ft.
Patching, ft~
Pumping, ft.
~ Table 820. Photo 1 og 20 .
~ t..~ .1/ A_,. ~ ~
<?_,. 0' .. J't ~. ..
""'~ 1o Slight Moderate Severe J'J' t-
~
4' F N F N F N
Transv., ft. 1540 53
Long., ft.
Alliq., ft. 2
Flushing, ft~
Patching, ft~
Pumping, ft.
186
~ Table 821. Photo log 21. ~ ,t..(.Q ~> ;.c..~ •
.1~ ~ <?~.
()' .. J't' ·~.
Slight .. Moderate Severe ~~ 1o J'J' (< .. 4' F N F N F N
Transv ... ft. 1181 47
Long., ft.
Allig., ft. 2
Flushing, ft~
Patching, ft~
Pumping, ft.
~ Table 826 Photo 1 og 22 .
~ ,t..(.Q ~> ;.c..~. ~ ~
<?~. ()' ..
J't' ~. ~(.Q ..
1o Slight Moderate Severe J'J' t
.. 4' F N F N F N
Transv., ft. 1158 22
Long., ft.
Allig., ft. 2
Flushing, ft~
Patching, ft~
Pumping, ft.
187
~ Table 823· Photo log 23· ~· ""~~.
/.1. ~ l'
~· ~0' ;;), ..
;(:-_ ..rt Sli'ght Moderate ~~ ..
16 Severe J'J' " .. 4- F N F N F N
Transv ... ft. 1210 8
Long., ft.
Allig., ft. 2
Flushing, .ft~
Patching, ft~
Pumping, ft.
~ Table 824 Photo 1 og 24 .
;<'- ""~ ~> ""~· /~ ~
G>~- 0' .. ;<'-. st ;. ..
16 Slight Moderate Severe ~J' s " .. 4- F N F N F N
Transv., ft. 943 62
Long., ft.
Alliq., ft. 2
Flushing, ft~
Patching, ft~
Pumping, ft. 17
188
~ Table 825 . Photo log 25. ~· ~{0_., ~~ "lc
<?_,. {00" :.J;
s .# ;('-.
. cc.., .. Slight Moderate Severe {OS 1o s (!<
"-P F N F N F N
Transv .• ft. 1223 19
Long., ft.
Allig., ft. 2
Flushing, ft~
Patching, ft~
Pumping, ft.
~ Table B2o Photo 1 og 26 .
;('- ~{0
"~ ""->· ~ ~-
<?,>. 0" .. sec ;('-.
;, .. 1o Slight Moderate Severe {OS s ~
"-P F N F N F N
Transv., ft. 1159 62
Long., ft.
A 11 i g. , ft. 2
Flushing, ft~
Patching, ft~
Pumping, ft.
189
{o Table 827. Photolog 27 • ~· ~~..,
.1.1. ~~ ~ -..;.,
<?~. ()' .. .;(:'-_
J'(C .. Slight Moderate Severe ;,~ 1o J'J' 't< .. + F N F N F N
Transv ... ft. 1251 12
Long., ft.
Allig., ft. 2
Flushing,. ft~
Patching, ft~
Pumping, ft.
~ Table B2ey Photo 1 og 28 .
~· "'<9.., .1.1. 'ic
<?,. ~QI' -..;., ..
,;(:'-. J't ;, .. 1o Slight Moderate Severe <9s
J' 't< .. 4' F N F N F N
Transv., ft. 1063 5
Long., ft.
Alliq., ft. 2
Flushing, ft~
Patching, ft~
Pumping, ft.
190
~ Table B29. Photo 1 og 29 . ~· to-~..,.. /~ ;)t
<?;). ~0' ;.),.-..
/:'-. S' . t..,.. ~ Slight Moderate Severe ~J' 16 J' t
"+ F N F N F N
Transv .• ft. 1118 6
Long., ft.
Allig., ft. 2
Flushing,. ft~
Patching, ft~ 5
Pumping, ft.
Table B30 Photolog 30. ~
/:'- to-~ ;)> il'>. ~ ~
<?). 0' .. J'cc /:'-. ..,.. ~
Slight Moderate Severe ~J' 1o J' t ~4'
F N F N F N
Transv., ft. 1038 28
Long., ft.
A 11 i q. , ft. 2
Flushing, ft~
Patching, ft~
Pumping, ft.
191
J(o Table 831. Photol og 31. ~· t.-(0;,
/.1. )~
~· (0()' :.J,
.I~. J'l"
"' Slight Moderate Severe ;,(0 16 J'J' t "' 4' F N F N F N
Transv .• ft. 1258 7 . Long., ft.
Allig., ft. 2
Flushing,_ ft~
Patching, ft~
Pumping, ft. 2.
~ Table 832. Photo 1 og 32 .
~ t.-(0 '/ ..... ,. /~ ~
<?,. 0' "' J'c-c ~.
;,(0 "' 4o Slight Moderate Severe J'J' t
"';f.' F N F N F N
Transv., ft. 780 5
Long., ft.
Allig., ft. 2
Flushing, ft~
Patching, ft~
Pumping, ft.
192
APPENDIX C
Force Ductility/Computer Program
193
The following computer program listing provides instructions for a
Hewlett-Packard Model 868 microcomputer to obtain the digitized signal
from a Bascom-Turner Model 8120T X-Y recorder via the HP-82939A Serial
Interface Option 001. The Hewlett-Padkarct Model 86-B microcomputer
system was equipped with parallel coupled HP-9121 disc drives, HP-829058
printer, HP-7470 A plotter, I/0 ROM, and Plotter ROM. Two Schaevitz
FTA-G-10000 force cells were coupled to the B-T 8120T by a Validyne MCl-3
chassis containing two CD-148 carrier demodulators and a PS-238 power
supply.
Force-t~e information obtained during testing was reduced by this
program to provide the seven force ductility parameters reported herein.
Steps involved in performing force ductility tests with the above
system are as follows:
1. Signal conditioner 'on' 2. Power & plotter on B-T 'on' [Hello] 3. HP Plotter 'on' 4. HP 86B drives and monitor 'on' 5. Load "Data Acquisition/Reduction" program 6. Remove "DA/R" pr()(]ram disc, replace with 2 initialized data discs 7. HP plotter 'on', paper 'in' 8. B-T: 'Status 11 (',()' [100] 9. B-T: 'ACQ 1 GO' 10. Check #1 load cell for response on B-T volt meter 11. B-T: 'CLEAR' 12. B-T: 'Status 12 GO' [1001 13. B-T: 'ACQ 2 GO' 14. Check #2 load cell for response 15. B-T: 'CLF..AR' 16. B-T: 'Status 11 C£)', '5000 GO', 'Status 12 GO', '5000 GO' 17. Turn on force ductility machine motor w/ clutch disenqaqeci 18. B-T: 'ACQ 12 r~· (Starts ~ata sampling) 1q. Engage clutch 20. Sample data until failure or specimen reaches end of machine 21. B-T: 'ACQ q GO' (Stops ·data sampling) 2 2 • HP: ' Run ' 23. HP: Monitor should ask following questions: 24. HP: Voltage SAtting? (8-T should he set to 10 but answer is '1' 25. HP: Time Setting? '5000' 26. HP: Filename for Data Set #1 'Appropriate Name' 27. Continue to answer_ questions on monitor until FINISHED messaqe
194
DATA TRANSFER/REOOCTION PROGRAM
10 OPI'ION BASE 1
20 DISP "*****************CHANGE PAPER IN PI.DITER******************"
30 DISP
40 DISP
50 DISP "VOLTAGE SETTING ?"
60 INPUT V
70 DISP "TIME SEITING ?"
80 INPUT T
90
100 CONTROL 10,3 8
110 CONTROL 10,4 26
120 CONTROL 10,2 2
130 CONTROL 10,5 48
140 DIM HH$(119)[60] ,D$[100] ,B$[70] ,C$(15)[70]
150 DIM F( 500) ,FT( 2,500) ,ESS( 2,500), TSS( 2,500), ECON( 4 ,3), TCON( 4,3)
160 DIM FTS(500),POINTS(4,2),EPOINTS(4,2),TPOINTS(4,2)
170 FOR MM=1 'ID 2
180 DISP "FILRNAME FOR S'IDRING DATA SET",MM
190 INPUT FILES$
200 A=4
210 MASS STORAGE IS ":0700"
220 IF MM=2 THEN 450
221 ooro 2so
230 DISP "LAB MIX NUMRER ?"
240 INPUT B$
250 C$(l)="EL PASO IAB MIX"
251 ooro 270
260 C$(1)[22,23]=8$
270 C$(2)="% REP "
280 DISP "RUBBER PERCENT BY WEIGHT ?"
290 INPUT 8$
300 C$(2)[1,2]=8$ 195
310 DISP "RUBBER TIPE ?"
320 IN:RJT B$
330 C$(2) [5,18]=B$
340 DISP "REPETITION NUMBER ?"
350 INPUT B$
360 C$(2)[24,24]=BS
370 DISP "TEST TEMPERA'IURE ?"
380 INPUT B$
390 CS ( 3) = "TEST TEMPERA'IURE ?"
400 C$(3)[19,21]=BS
410 DISP "TEST DATE ?"
420 INRJT B$
430 C$(4)= "DATE ?"
440 CS(4) [7,15]=BS
450 IF MM=1 THEN FILE1$=FILES$
460 IF MM=2 THEN FILE2$=FILES$
470 NP=O
480 FL=O
490 DISP "ENTER CAL 41 ON DATACENTER 'IHEN PRESS OONT. "WHEN SCREEN
CLEARS TfiEN PRESS GO ON DATACF.N'IER"
500 PAUSE
510 CLEAR
520 DISP "DATA TRANSFER IN PFOGRESS"
530 FOR I=1 10 119
540 EN'IER 10 ; DS
550 HH~(I)=D$
560 FC=roS (HH$(I),".")
570 IF PC>O THEN 600
580 NEXT I
590 IP 1>119 THEN I=llQ
600 K=I
610 FOR I=l 'IO K
620 DP=IDS (HH$(I),".")
630 IF DP=O '!HEN 730
196
640 SP=DP-3
650 EP=SP+ 32
660 COOR=LRN (HH$(I))
670 IF COOR<47 THEN EP=EP-48+000~+1
680 FOR J=SP 'IO P.P STEP 8
690 NP=NP+l
700 BS=HH$( I) [,J ,,J+71
710 F(NP)=VAL (HH$(3)[33,351)
720 NEXT ,J
730 NEXT I
740 NP=VAL (HH$(3)[33,35]
750 CLEAR
760 DISP "INPUT COMPLETE: ProCESSING IN PROGRESS"
770 GOSUB 970
780 XMAX-ARS (F(l))
790 FOR I=2 'ID NP
800 Xl=ABS (F(l))
RIO IF X1>XMAX THEN XMAX=Xl
820 NEXT I
830 IF XMAX<91.97 THEN 910
840 SF=91.97 THEN 910
850 FOR I=1 'ID NP
860 F(I)=SF*F(I)
870 NEXT I
880 DISP "'ffiE SCALING FAC'IDR IS " :SF
890 IF MM=2 'IHEN 950
900 GO'ID 915
910 SF=l @ GOTO 8RO
915 BEEP 150,800
920 DISP "PRESS CAL 22 ON DATACF.N'IER '!HEN PRESS CONT''
930 PAUSE
940 CLFAR
950 NEXT MM
960 GOID 1190
197
970 NB=(2*NP+2)*8+A*60
980 FILE$=FILES$
990 ER=O
1000 ON ERROR GOSUB 5420
1010 CRF~TE FILE$,1,NB
1020 IF ER=1 THEN 990
1030 OFF ERROR
1040 FOR I=1 'IO NP
1050 F(I)=F(I)*V/10
1060 FT(1,I)=F(I)&5
1070 FT(2,I)=I*T*10A-3/60
1080 NEXT I
1090 ASSIGN# 1 TO FILE$
1100 PRINT# 1 ; NP,A
1110 FOR I=1 m A
1120 PRINT* 1 ; C$(I)
1130 NEXT I
1140 FOR I=1 'IO NP
1150 PRINT# 1 ; FT (1,I),FT(2,I)
1160 NEXT I
1170 ASSIGN# 1 TO *
1180 RE'IURN
1190 GCLFAR
1200 DEG
1210 EFLAG=O
.1220 FOR I=l 'IO 15
1230 C$(I)=" II
1240.NEXT I
1250 DE=.2333333
1260 FOR MM=1 'ID 2
1270 IF MM=1 THEN A$=FILE1$
1280 IF MM=2 THEN A$=FILE2$
1290
1300 ! READ FILE FPOM DISC
198
1310
1320 DISP "OBTAINIJ\G FORCE-TIME DATA FROM TA.PE"
1330 ASSIGN# 1 TO AS
1340 RFAD# 1 : NP,NL
1350 FOR I=1 ~ NL
1360 PEAD#1 : B$
1370 C$(I)=R$
13RO NEXT I
1390 FOR I=1 'IO NP
1400 READ# 1 ; FT(1,I),FT(2,I)
1410 NEXTI
1420 CLFAR
1430
1440 DISPLAY FILE INFORMATION
1450
1460 DISP "********************FILE INFORMATION*********************"
1470 DISP
1480 OISP
1490 FOR I=1 'IO NL
1500 DISP C$ (I)
1510 NEXT I
1520 DISP
1530 DISP
1540 DISP "*********************************************************"
1550 ASSIGN# 1 TO * 1560 TL=LEN (A$)
1570 ·FILE$=.2\_$
15RO IF DF.<.25 THEN FILE$[TL+1]="A''
1590 IF DF.>.25 'IHEN FILE$[TL+1]="B"
1600 DISP
1610 DISP
1620 OISP
1630 DISP "DA_TA BEING PROCESSED"
1640
199
1650 ! ZERO OUT ARRAYS
1660 !
1670 ~R I=1 TO 500
1680 ESS(1,I)=O
1690 ESS(2,I)=O
1700 'JSS(1,I)=O
1710 TSS(2,I)=O
1720 FTS(I)=O
1730 NEXT I
1740 ~R I=1 TO 4
1750 FOINTS(I,1)=0
1760 FOINTS(I,2)=0
1770 EFOINTS(I,1)=0
1780 EFOINTS(I,2)=0
1790 TFOINTS(I,1)=0
1800 TFOINTS(I,2)=0
1B10 FOR J=1 'ID 3
1820 ECON(I,J)=O
1830 TCON(I,J)=O
1840 NEXT J
1850 NEXT I
1860
1870 CONVERT, SMCXYIH, AND CALCUlATE STRESS-STRAIN VALUES. ALOO
1880 DF.TERMINE MAXIMUM VALUFS AND AREAS UNDER CURVES
1890
1900 TF.MP=NP-2
1910 FAREA=O
1920 TARFA=O
1930 MESTRESS=O
1940 MTSTRFSS=O
1950 MFORCE=O
1q60 NUMPT=O
1970 FOR I=1 'ID NP
1980 IF I<50 AND FT(1,I)<=O THEN 2130
200
1990 IF I<3 THEN FTS(I)=FT(1,I) @ GOTO 2020
2000 IF I>TEMP THP.N FTS(I)=FT(1,I) ~ GOTO 2020
2010 FTS(I)=(FT(l,I-2)+FT(1,I-1)+FT(1,I)+FT(l,I+1)+FT(l,I+2))/5
2020 ESS(2,I)=DE*FT(2,I)
2030 ESS (1,I)=FTS(I)*2.54~2
2040 TSS(2,I)=DOG (l+ESS(2,I))
2050 TSS(l,I)=FTS(I)*(1+DE*FT(2,I))*2.54~2
2060 IF I=1 TH~ 2090
2070 FARFA=F.ARF.A+( ESS( 1, I)+ESS( 1 ~ I-1)) *(F.SS*( 2 ,t)~ESS( 2,I-1)) /2 2080 TARFA=TARFA+(TSS( 1 ,I)+TSS( 1 ,I-1 ).)*(TSS*(2,I)-TSS( 2,I-1) )/2
2090 MESTRESS=MAX (~ESTRESS,FSS(l,I))
2100 M'ISTRESS-MAX ( MTS'IRESS, 'ISS ( ·1 , I ) )
2110 MFORCE=MAX ( MFORCE, F'IS ( I) )
2120 NUMPT=NUMPr+ 1
2130 NEXT I
2140 MESTRAIN=ESS(2,NP)
2150 MTSTRAIN=TSS(2,NP)
2160 YLIM=40
2170 XLIM=CEIL (MFORCE)
21RO PDDTTER IS 705
2190 LIMIT 10,250,10,190
2200 IF MM=1 'mEN LOCATE 5,50,20,90
2210 IF MM=2 'IHEN LOCATE 70,115,20,90
2220 SCALE XLIM,O,O,YLIM
2230 IF XLIM<=2 THEN XTIC=.1 ELSE XTIC-.5
2240 XNUMM=XLIM+1
2250 AXES XTIC,5,0,0,1,1
2260 AXES XTIC,5,XLIM,40,1,1
2270 DEG
2280 I.DIR 90
2290 IORG 5
2300 CSIZE 2
2310 YNUM$=" o.o" 2320 YNUM=O
201
2330 FOR !=1 '10 q
2340 MOVEO,YNUM
2350 SETGU
2360 Ir.DVE 2,0
2370 LABEL YNUM$
2380 YNUM=YNUM+5
2390 YNUM$[1,2]=VAL$ (YNUM)
2400 SETUU
2410 NEXT I
2420 MOVE 0,17.5
2430 SE'ffiU
2440 !MOVE 5,0
2450 LABEL "TIME - MINUTES"
2460 SETUU
2470 MOVE 0,0
2480 IDRG 8
2490 XNUM=O
2500 XNUM$=" o.o" 2510 FOR !=1 TO XNUMM
2520 MOVE X~mM,O
2530 SE'IGU
2540 !MOVE 0,-1
2550 IABEL XNUM$
2560 XNUM=XNUM+1
2570 XNUM$[1,2]=VAL$ (XNUM)
2580 SETUU
2590 NEXT I
2600 IORG 5
2610 LDIR 180
2620 XLIM=XLIM/2
2630 MOVE XLIM,O
2640 SE'IGU
2650 IK>VE 0,-8
2660 IABEL "FORCE - roUNDS"
202
2670 SETUU
2680 MOVE 0,0
2690 FOR !=1 ID NP
2700 PDOT FTS(I),FT(2,I),-1
2710 NEXT I
2720 PF.N U
2730 SCALE 0,1,0,1
2740 MOVF. .08,.65
2750 IORG 1
2760 LDIR 90
2770 FOR !=1 TO 4
2780 lABEL CS ( I)
2790 NEXT I
2ROO IF MM=1 'IHEN IABEL "LOAD CELL 1"
2810 IF MM~2 'THEN LABEL "LOAD CELL 2"
2820 PEN UP
2830 LIMIT 0,10,0,10
2840 MOVE 0 , 0
2850 PEN 0
2860 ! PlOT STRESS-STRAIN CURVES AND DETERMINE RffiiONS OF CDNSTANT
COMPLIANCE
2870 !
2880 PIOTTER IS 1
2890 I.DCA'IE 15,160,25,85
2900 FXD 1
2910 FOR K=1 TO 2
2920 DISP
2930 DISP
2940 IF K=1 '!HEN XLIM=CEIL (MESTRAIN)
2950 IF K=1 THEN YLIM=CRIL (MESTRESS)
2960 IF K=2 THEN XLIM=CEIL (MTSTRAIN)
2970 IF K=2 'IHEN YLIM=CEIL ( MTSTRESS)
2980 XINC=.1 @ YINC=YLIM
2990 XTIC=lO @ YTIC=l
203
3000 SCALE O,XLIM,O,YLIM
3010 LAXES -XINC,YINC,O,O,XTIC,YTIC
3020 AXES XINC,YINC,XLIM,YLIM,XTIC,YTIC
3030 MOVE XLIM/2,0
3040 SE'IGU
3050 Il\DVE 0,-8
3060 IDIR 0
3070 IDRG 5
3080 lABEL "STRAIN - IN/IN"
3090 SE'IUU
3100 MOVE O,YLIM/2
3110 SE'IGU
3120 IMOVE -12,0
3130 LDIR 90
3140 lABEL "STRESS - PSI"
3150 SETUU
3160 LDIR 0
3170 IF K=2 THEN 3220
3180 FOR I=1 'IO NP
3190 PDOT ESS(2,I),ESS(1,I),-1
3200 NEXT I
3210 GO'ID 3250
3220 FOR I=1 '10 NP
3230 PIDT TSS(2,I),TSS(1,I),-1
3240 NEXT I
3250 SE'IGU
32fi0 MOVE 3,6
3270 IDRG 0
3280 LABEL "NUMBER OF' RffiiONS OF CONSTANT SIDPE ? - ( 1 NUMBER)"
3290 INPUT NUMRffi
3300 IF K=1 'mEN NUMEP=NUMRffi
3310 IF K=2 'IHEN NUMTP=NUMRffi
3320 GCLEAR 9
33 30 NUMRffi1 =NUMRFG+ 1
204
3340 STFIAG=O
3350 FOR I=1 TO NUMREG1
3360 IFIAG=O
3370 SE'ffiU
3380 MOVE 3,6
3390 IF I=NUMREGl THEN 3520
3400 LA'REL "ENTER START AND END FOINTS FOR RffiiON II :I:" (X.l-X2) II
3410 INRJT POINTS (I,1),FOINTS(I,2)
3420 C.,CLEAR 9
3430 SETUU
3440 CX=XLIM/346.305
3450 IDINTS(I,l)=INT (IDIN'IS(I,l)/DX)*DX
3460 PP.N -2
3470 FOR J=IDIN'IS( I ,1) 'IO IDIN'IS( I ,2) STEP DX
3480 MOVE J • 0
3490 D~ J,YLIM
3500 f\lEXT \J
3510 OO'IO 3730
3520 SE'IGU
3530 MOVE 3, 6
3540 lABEL "INPUT STRAIN AT FAILURE - (Xl)"
3550 INPUT STRAINF
3560 PEN -2
3570 SE'IUU
35RO MOVE STRAINF,O
3590 DRAW STRAINF, YLIM
3600 SE'.IGU
3610 PEN 1
3620 IF STFLAG=1 'IHEN S'IFIAG=O ~ OO'ID 3520
3630 PEN 1
3640 GCLEAR 9
3650 roVE 3,6
3660 lABEL "'ID RE-SPECIFY STRAIN AT FAILURE ? - (Y/N) 11
3670 INRJT D$
205
3680 GCLF.AR 9
3690 IF D$="Y" 'lliEN STFIAG=1 @ OO'ID 3560
3700 IF K=1 THEN FESTRAIN=STRAINF
3710 IF K=2 THEN FTSTRAIN=STRAINF
3720 GO'IO 3870
3730 MJVE 0,0
3740 IF IFIAG=1 'IHEN PEN 1 @ GO'IO 3360
3750 SE'IGU
3760 MOVE 3,6
3770 PEN 1
3780 lABEL "TO RESPECIFY IN'IERVAL ? - (Y/N)"
3790 INR.JT 0$
3800 GCLFAR 9
3810 IF D$="N" 'IHEN 3A50
3820 IFLAG=1
3830 SE'IUU
3840 OO'IO 3460
3850 IF K=l THEN EBOINTS(I,1)=FOINTS(I,1) @ EBOINTS(I,2)=FOINTS(I,2)
3860 IF K=2 THEN TFOINTS(I,1)=FOINTS(I,1) @ TFOINTS(I,2)=FOINTS(I,2)
3A70 NEXT I
3880 PEN 1
3890 GCLEAR
3900
3910 ! DETERMINE VALUES OF CONSTANT CDMPLIANCE
3920 1
3930 NEXT K
3940 CLEAR
3950 DISP "DATA BEING PROCFSSED"
3960 FOR K=l TO 2
3970 IF K=2 TH~l END1=NUMEP
3980 IF K=2 THEN ENDl=NUMTP
3990 TEMP=1
4000 FOR J=1 TO ENOl
4010 LBffi=TEMP
206
4020 SX=O
4030 SY=O
4040 SXY=O
4050 SX2=0
4060 NFOINT=O
4070 FOR I=LBffi 10 NP
4080 IF K=2 THEN 4180
4090 IF ESS(2,I)<EIDINTS(J,1) '!HEN 4250
4100 IF ESS(2,I)>EIDINTS(J ,2) 'IHF.N 4270
4110 SX=SX+ESS(2,I)
4120 SY=SY+ESS(1,I)
4130 SXY=SXY+ESS(2,t)*ESS(1,I)
4140 SX2=SX2+ESS(2,I)A2
4150 NFOINT=NFOINT+1
4160 ~P=TEMP+1
4170 OOID 4260
4180 IF TSS(2,I)<TPDINTS(J,1) THEN 4250
4190 IF TSS(2,I)>TIDIN'IS(J,2) 'IHEN 4270
4200 SX=SX+TSS(2,I)
4210 SY=SY+TSS(1,I)
4220 SXY=SXY+TSS(2,I)*TSS(l,I)
4230 SX2=SX2+TSS(2,I)A2
4240 NFOINT=NFOINT+l
4250 TEMP=TEMP+ 1
4260 NEXT I
4270 TEMP=TEMP+l
4280 XBAR=SX/NBOINT
4290 YRAR=SY/NFOINT
4300 SDOPE=(SXY-NFOINT*XBAR*YBAR)/(SX2-NFOINT*XBARA2)
4310 IF K=2 'IHEN 4360
4320 ECON(J,1)=SLOPE
4330 ECON(J,2)=EFOINTS(J,1)/DE
4340 ECON(J ,3)=EF.OINTS(,J ,2)/DE
4350 GOID 4390
207
4360 TOON(J,1)=SDOPE
4370 TOON(J,2)=(EXP (TFOINTS(J,1))-1)/DE
4380 TOON(J,3)=(EXP (TFOINTS(J,2))-1)/DE
4390 NEXT \J
4400 NEXT K
4410 PRINTER IS 703
4420 PRINT "********************************************************"
4430 PRINT "********************************************************"
4440 PRINT
4450 PRINT
4460 FOR !=1 'ID NL
4470 PRINT USING 4490 ; C$(I)
4480 NEXT I
4490 IMAGE 20X,50A
4500 LOC=IDS (A$, "M")
4510 C$(NL+l)="LOAD CELL NUMBER:"
4520 C$(NL+l)f19]=AS[8,8] ! *********CHANGED FOR RUFFAID MIX********
4530 PRINT USING 4490 ; C$(NL+1)
4540 C$(NL+2)="STRAIN RATE:"
4550 C$(NL+2)[14,18]=VAL$ (DE)
4560 PRINT USING 4490 ; C$(NL+2)
4570 PRINT
4580 PRINT
4590 PRINT "MAXIMUM ENGINEERING S1RESS:" ,TAB (60) ;INT
(100*MESTRESS)/100
4600 PRINT "MAXIMUM TRUE STRESS:" , TAB ( 60) ; IN'I' ( 1 OO*MTS'IRESS) /100
4610 PRINT
4620 PRINT "ENGINEERING STRAIN AT FAILURE:" ,TAB (60) ;FES'ffiAIN
4630 PRINT "TRUE STRAIN AT FAILURE:" ,TAB (60) ;FTSTRAIN
4640 PRINT
4650 PRINT "AREA UNDER ENGINEERING STRES8-S'IRAIN CURVE:" ,TAB (60) ;!NT
(lOO*EARFA)/100
4660 PRINT "ARF.A UNDER TRUE STRESS-STRAIN CURVE:" , TAB ( 60) ; TNT
(100*TARFA)/100
208
4670 PRINT
4680 PRINT
4690 PRINT USING 4720
4700 PRINT USING 4730
4710 PRINT USING 4720
4720 IMAGE 23X,"*********************************"
4730 IMAGE 23X, "* CDNSTANT VALUES OF SLOPE *"
4740 PRINT
4750 PRINT
4760 PRINT USING 4800
4770 PRINT USING 4810
47RO PRINT USING 4820
4 790 PRINT USING 4830
4800 IMAGE 15X,"I.DWER LIMIT" ,lOX,"UPPER LIMIT"
4810 IMAGE 15X, "OF TIME .. ,lOX, "OF TIME II ,lOX," . SI.DPE "
4820 IMAGE "CURVE" ,lOX, "INTERVAL (MIN)", 7X, "INTERVAL (MIN) II, 7X, .. PSI"
4830 IMAGE "-------------------------------------------------------" 4840 FOR I=l 'IO NUMEP
4850 PRINT TJSING 4870 ~ FrON(I,2),F.CON(I,3),ECON(I,l)
4860 NEXT I
4870 Ir.1AGE "ENG." ,llX,MD.DDDE,llX,MD.DDOE,llX,MD.nDDE
4880 IMAGE "'IRUE",llXMD.DDDE,llX,MD.DDDE,llX,MD.DDDE
4890 FOR I=l 'IO NUMTP
4900 PRINT USING 4880 'ICON(I,2),'IU)N(I,3),TCON(I,l)
4910 NEXT I
4920 PRINT
4930 FOR I=l 'IO 8
4940 PRINT
4950 NEXT I
4960
4970 S'IDRE REStJL'IS ON TAPE
4980
4990 MASS S'IORAGE IS ":0701"
SOOO ER=O
209
5010 ON ERROR GOSUB 5420
5020 CREA.'IE FILE$ ,1,1140
5030 IF ER=1 THEN 5000
5040 OFF ERROR
5050 CS(NL+1)="E~. STRAIN AT FAILURE:"
5060 C$ (NL+2 )="MAX. Ef\lG. S'IRESS:"
5070 C$(NL+3)="TRUE STRAIN AT FAILURE:"
5080 C$(NL+4)="MAX. 'IRUE STRESS:"
5090 C$(NL+5)="AREA UNDER ENG. CURVE:"
5100 C$(NL+6)="A:REA UNDER TRUE CURVE:"
5110 C$ (NL+ 1) [24 ,29] =VAL$ ( FESTRAIN)
5120 C$(NL+2)[19,24l=VAL$ (MESTRESS)
5130 C$(NL+3)[24.29]=VAL$ (FTSTRAIN)
5140 C$(NL+4)[19,24]=VAL$ (MTSTRESS)
5150 C$(NL+5)[24,29]=VALS (FARFA)
5160 C$(NL+6)[24,29]=VAL$ (TARFA)
5170 NSL=NL+6
5180 ASSIGN# 1 TO FILE$
5190 PRINT# 1,1 ; NSL,C$(),EOON(,)
5200 ASSIGN# 1 TO * 5210 MASS STORAGE IS 11 :0700"
5220 CLFAR
52 30 ('.,CLEAR
5240 NEXT MM
5250 PI.DTIER IS 1
5260 SCALE 0,10,0,10
5270 I.DRG 5
5280 FOR ANG=1 'IO 15
5290 CSIZE 30,.6,ANG
5300 MOVE 5,5
5310 lABEL 11 FINISHED"
5320 NEXT ANG
5330 FOR I=1 ID 30 @ NEXT I
5340 CLFAR
210
5350 FOR I=l '10 6
5360 ALmA
5370 FOR J=l TO 150 @ NEXT J
5380 GRAm
5390 FOR J=l 'IO 150 @ NEXT \J
5400 NEXT I
5410 END
5420 OFF ERroR
5430 ERNTJM=ERRN
5440 IF ERNUM#63 THEN 54BO
5450 DISP "FILE ";FILE$;" ARFADY ON OISC. EN'IER NEW FILENAME."
· 5460 INPUT FILE$
5470 OO'IO 5510
5480 DISP "DISC FULL. PUT IN NE.W DIS<; ANp 'JJ:'F.N PRESS CONT."
5490 PAUSE
5500 INITIALIZE "DRIVEl"
5510 ER=l
5520 RETURN
5530 END
109207
211
APPENDIX D
Force Ductility/Double Ball Softeninq Point Data
212
N t-' w
Table 01. Maximum Engineering Stress, psi (MES) El Paso Lab Mix 39.2F.
~ A B
22 24 26 22 24 26
35.6 36.1 30.2 37.1 39.9 37.1 ~ 32.9 17.8 22.9 30.5 24.9 10.8 0 23.3 17.2 23.0 20.1 15.5 23.0 _J
41.4 42.6 10.5 41.6 27.1 11.8 "'0
23.3 19.2 19.7 20.3 10.3 11.0 0 :E 26.6 19.6 14.3 12.1 16.2 18.3
28.3 16.7 39.3 15.2 20.9 14.8 ...c: 18.0 32.0 14.5 20.3 12.0 18.0 0')
•r-20.5 18.4 18.0 21.4 19.5 11.8 :c
- --- - --
c
22 24 26
34.8 33.8 34.3 I
I
35.4 29.2 18.5 28.0 20.0 23.5
35.2 31.7 32.6 41.5 24.8 35.1 20.1 17.0 13.0
40.4 45.0 16.4 14.1 20.8 20.2 34.1 13.9 22.6
N ......, +="'
Table 01, (continued). El Paso Lab Mix 39.2F (MES).
Source df ss Rubber 2· 571.2
Concentration 2 646.4
Digestion 2 418.1
R X C 4 10.1
R x D 4 157.2
c X D 4 121.3
R X c X D 8 298.4
Error 54 4854.2
Total 80 7077.7
MS F Pr > F
186.1 3.18 0.05
323.2 3.59 0.03 209.1 2.33 0.11
2.5 0.03 0.99
39.0 0 .. 44 0 78 30.1 0.34 0.85
I
37.2 0.41 0.91 I
90.0
N 1--' V1
Table 02. Maximum True Stress, psi (MTS) El Paso Lab Mix 39.2F.
, A B ~
~
22 24 26 22 24
101.6 107.2 85.8 122.0 145.2 ~ 80.0 48.0 61.6 86.4 76.2 0 _J 54.0 41.8 74.2 84.8 64.8
154.4 152.0 25.7 170.4 127.4 "0 75.2 49.0 60.2 64.8 33.0 0 ::E 90.2 52.2 38.2 50.6 71.4
117.4 67.8 164.8 67.0 108.6 -'= 57.2 139.4 43.6 106.6 58.2 C') .,...
81.8 70.0 73.4 106.2 97.6 :r:
c
26 22 24 26
153.2 106.0 113.0 108.6 51.6 116.6 87.8 50.8
109.8 91.6 57.2 100.2
51.8 158.0 147.8 156.0 37.8 199.6 103.0 163.2 91.4 66.2 45.4 40.6
76.4 227.2 299.2 95.4 I
97.2 119.6 119.6 123.8 I 63.2 179.6 79.0 138.4
N f--1 0"\
Table 02, {continued). El Paso Lab Mix 39.2F (MTS).
Source df ss Rubber 2 21802.1
Concentration 2 5788.2
Digestion 2 5162.2
R X C 4 759.5
R x D 4 9777.4
C X 0 4 3667.4
R X c X D 8 4988.8
Error 54 113552.1
Total 80 165499.7
MS F Pr > F 10901.0 5.18 0.01
2894.1 1.38 0.2·6
2581.1 1.23 0.30
190.1 0.09 0.99
2444.1 1.16 0.34
917.1 0 . .44 0.78
624.1 0.30 0.96
2102.0
Table 03. Maximum Engineering Strain, in/in (ESF) El Paso Lab Mixed 39.2F.
:, A B c ~
> 0
22 24 26 22 24 26 22 24 26 I
' -
3.18 3.34 3.19 3.72 3.11 4.26 4.40 4.69 4.13 ~ 3.27 3.84 3.60 3.45 3.38 5.82 4.26 4.70 5.10 0 _J 3.35 3.26 3.68 4.55 5.08 4.37 4.50 4.75 5.59
~ 3.00 3.18 3.34 3.30 4.58 4.38 4.17 4.61 4.40
0 3.92 3.65 3.80 4.03 4.84 4.63 4.39 4.68 4.21 ::E
3.98 3.51 3.58 5.60 4.64 4.67 4.95 4.91 4.86 .,
.s::::. 4.04 3.90 3.73 4.66 5.00 5.10 5.30 5.04 5.68 C) 3.91 3.87 3.89 5.25 4.77 5.43 5.87 5.69 6.00
•r-:I: 4.20 3.94 4.26 4.73 5.00 5.69 4.71 5.51 5.71
-----~-------L__ ____ ·-·----
------·-~
Table 03, (continued). El Paso Lab Mix 39.2F (ESF).
N 1--' 00
Source Rubber
Concentration Digestion
R X C
R X D C X D
R X C X 0 Error
Total
df ss 2 22.73
2 1.01
2 8.18
4 0.93
4 0.95
4 0.90
8 0.82
54 10.86
80 46.39
MS F Pr > F I
11.36 56.5 0.0001 i I
!
0.51 2.5 0.09 ;
4.09 20.4 0.0001
0.23 1.2 0.34
0.24 1.2 0.33 I
0.23 1.1 0.36
0.10 0.5 0.84 0.20
N 1-' \0
Table 04. Maximum True Strain, in/in (TSF) El Paso Lab Mix 39.2F .
...
~ A B ~ y.-0
22 24 26 22 24 ..
1.43 1.48 1.43 1.54 1.41 ~ 1.45 1.57 1.52 1.60 1.48 0 _J 1.41 1.45 1.54 1.71 1.80
1.57 1.43 1.47 1.47 1.73 "'0 1.59 1.53 1.57 1.64 1.75 0 :E 1.59 1.51 1.53 1.89 1.73
1.61 1.58 1.55 1.73 1.78 .s:::. 1.59 1.59 1.57 1.84 1.75 CTI •r- 1.65 1.59 1.66 1.74 1.80 :c
c
26 22 24 26
1.44 1.69 1.93 1.63 1.92 1.67 1.75 1.81 1.68 1.69 1.75 1.88
1.70 1.64 1.72 1.69 1.73 1.69 1.74 1.64 1.74 1.78 1.77 1.77
1.81 1.85 1.80 1.91 1.86 1.96 1.91 1.95 1.89 1.76 1.87 1.90
Table 04, {continued). El Paso Lab Mix 39.2F (TSF).
N N 0
Source Rubber
·Concentration Digestion
R X C
R X 0 c X D
R X C X D Error Total
L..---- --
df ss 2 0.835
2 0.030
2 0.287
4 0.033
4 0.029
4 0.024
8 0.036
54 0.367
·so 1.642
MS F Pr > F 0.418 61.38 0.0001
0.015 2.24 0.11 I
0.143 21.09 0.0001
0.008 1.20 0.32
0.007 1.05 0.39 0.006 0.89 0.47
0.005 0.66 0.72 0.007
N N ~
Table 05. Curve Area, psi (CA) El Paso Lab Mix 39.2F.
'
? ~
A ~ 0
22 24 26 22 ...
89.4 44.2 78.4 111.2 3 0 81.4 52.2 63.4 86.6 _J
56.8 42.2 69.8 77.6
""0 139.0 123.2 26.3 123.2
0 74.6 52.0 60.2 66.0 :::E
87.6 52.8 39.3 53.6
101.2 59.2 123.6 63.0 ,..e:
56.4 107.8 43.8 83.8 O"l .,.... 75.0 63.8 69.4 90.8 :I:
B c
24 26 22 24 26
112.2 139.2 112.0 118.8 110.2 I
67.8 50.6 115.4 97.2 64.4 64.4 89.8 94.6 66.6 105.0
113.8 45.2 129.6 134.2 129.2 36.0 38.5 163.6 99.6 133.2 65.6 65.6 73.0 55.6 46.6
90.0 59.4 173.2 173.4 81.4 52.4 86.6 66.6 101.8 97.2 85.8 59.6 133.2 . 70.0 105.2
Table 05, (continued). El Paso Lab Mix 39.2F (CA).
N N N
~
Source
Rubber
Concentration
Digestion
R X C
R X D
C X D
R X c X D
Error
Total
df ss 2 16124.0
2 4553.4
2 441.8
4 278.2
4 2431.4
4 2313.4
8 2604.0
54 55757.5
80 84507.7
MS F Pr > F 8062.0 7.81 0.001
2277.2 2.21 0.12 ''
220 .. 4 0.21 0.81
70.3 0.07 0.99
608.1 0.59 0.67
578.1 0.56 0.69
326.0 0.32 0.96
1033.1
Table 06. Asphalt Modulus, psi (AM) El Paso Lab Mixed 39.2F.
~ A B c ., .-2--0
22 24 26 22 24 26 22 24 26 ~
378.2 356.6 308.0 417.1 294.4 408.4 410.2 375.4 352.3 3: 312.3 160.3 210.0 351.1 159.6 118.1 420.5 305.3 169.4 0 _J 242.4 141.6 207.1 173.7 140.6 159.2 271.1 197.7 253.7
"'0 312.1 358.4 75.1 322.7 250.6 106.3 410.2 336.7 321.7
0 208.8 200.4 191.0 193.6 96.5 117.5 332.3 239.0 269.3 :E 205.9 154.1 111.8 107.1 154.1 136.1 209.4 157.1 115.4
266.8 161.2 256.7 94.5 168.0 138.0 233.3 259.4 106.2 i ..r::. 180.6 241.3 124.6 167.5 108.1 123.0 135.2 213.2 118.0
I Ol
189.2 187.7 178.2 193.0 157.0 103.1 271.1 119.1 135.3 •r-:c
Table 06, (continued). El Paso Lab Mix 39.2F (AM).
N N +:'-
L_ ___
Source
Rubber
Concentration
Digestion
R X C
R x 0 C X 0
R X C X 0 Error
Total ------ ------- -
df ss 2 54349.0
2 82777 .1 2 139914.2
4 2240.4
4 23995.5 4 16176.7
8 14214.1 54 358920.0 80 692590.0
-- ----- ----··--
MS F Pr > F
27175.0 4.09 0.02
41388 .o 6.23 0.003
69957.1 10.53 0.0001
560.1 0.08 0.99
5999.1 0 90 Q._4_7
4044.2 0.61 0.66
1777.0 0.27 0.97
6647.0
Tab 1 e 07. Asphalt-Rubber Modu 1 us, psi ·(ARM} El Paso Lab Mixed 39. 2F.
, A B c .#
~ 0
22 24 26 22 24 26 22 24 26 I
3 60.1 68.4 51.1 95.1 131.1 133.1 74.0 77.1 72.2
0 42.4 24.3 33.3 64.1 5.8.3 40.0 84.0 52.2 26.1 -' 23.3 21.0 50.4 66.0 48.4 106.2 65.2 32.4 75.0
\:J 124.3 128.5 11.0 174.1 114.5 45.1 141.1 119.4 143.0
0 48.2 25.4 35.4 46.3 20.4 26.3 186.3 80.3 153.1 :E:
62.1 29.4 13.0 36.5 59.1 75.5 41.5 24.0 23.1 I
104.0 53.4 164.4 51.2 103.3 66.4 226.6 278.3 85.2 ..c
38.0 132.3 27.3 100.2 49.3 86.1 53-4 116.2 119.3 C'l ·~ 65.4 52.0 58.2 101.3 92.1 50.0 186.8 66.6 134.4 :r:
N N 0"1
Table 07, (continued). El Paso Lab Mix 39.2F (AFM).
Source df ss Rubber 2 26776.4
Concentration 2 4078.3
Digestion 2 18937.2
R X C -4 1174.6
R x D 4 16186'.6
c X D 4 4761-.4
R X C X 0 8 6714.3
Error 54 131091.0
Total 80 209720.8 --- -~---~-------- -- . -- - -- ---
MS F Pr > F 13388.2 5.51 0~007
2039.1 0.84 0.44
9464.1 3.90 0.03
294.2 0.12 0.97
4046~2 1.67 0.17 1190.1 0.49 0.74
839.1 0.35 0.94
2427.0
Table DB. Maximum Engineering Stress, psi (MES) E1 Paso Field Mix 39.2F.
Rubber
A B c
19.5 17.2 28.1 N 22.0 10.8 21.0 C\J 19.6 28.9 30.4
~
.... c 27.2 26.4 25.7 0 ..... o::t" 24.0 ·24'.2 22.3 +-> C\J ~ 29.9 38.3 21.3
I s...
+-> c ClJ u c 0
I u 11.6 21.1 21.3
1.0 24.0 20.8 28.2 C\J 20.8 22.7 23.4
Source df ss MS F Pr > F
Rubber 2 29.2 14.6 0.55 0.59
Concentration 2 141.4 70.7 2.67 0.09
R X c 4 175.1 43.8 1.66 0.20
Error 18 475.6 26.4
Total 26 821.3
227
Table 09. Maximum True Stress, psi El Paso Field Mix 39.2F.
Rubber
A B c
55.4 56.4 111.6 N 77.8 36~4 80.4 N 68.0 118.2 123.4
~
.. 86.2 93.4 90.0 c:
0 64.2 91.4 64.4 .,... oo:::t +-' N 92.2 161.8 65.4.
I
n:::l ~ +-' c: QJ u c: 0 33.2 80.2 75.6 u
\0 78.0 80.4 131.4
N 60.8 92~4 96.6
Source df ss MS F Pr > F
Rubber 2 3271.3 1635.7 2.53 o~11
Concentration 2 4.87. 7 243.9 0.38 0.69
R x C 4 5382.4 1345.6 2.08 0.13
Error 18 11650.1 647.2
Total 26 20791.5
228
Table DlO. Maximum Engineering Strain, in/in El Paso Field Mix 39.2F.
Rubber
A B c
3.98 4.05 4.21 N 4.19 4.85 4.40 N
4.89 4.40 4.47
~
.. 3.04 .3.34 4.05 ~ 0 3.29 4.30 4.20 •r- q-+-' N 3.39 4.11 3.84 co s... +-' ~ QJ u c:
3.81 0 3.83 3.10 u 3.46 4.06 4.38
1.0 3.06 3.68 4.00 N
Source df ss MS F Pr > F
Rubber 2 0.906 0.453 3.07 0.071
Concentration 2 2.665 1.333 9.03 0.002
R X C 4 0.484 0.121 0.82 0.529
Error 18 2.656 0.148
Total 26 6.712
229
Table 011. Maximum True Strain, in/in El Paso Field Mix 39.2F.
Rubber
A B c
1.60 1.62 1.66 N 1.64 1.77 1.70 N 1.77 1.79 1.70
~
... 1.42 1.47 1.62 ~ 0 1.46 1.67 1.64 .,... q-....., N 1.47 1.63 1.57 ttS
·s.. ....., ~ Q) u c 0 1.56 1.57 1.39 u
1.49 1.63 1.69 \.0 1.40 1.55 1.61 N
Source df ss MS F Pr > F
Rubber 2 0.042 0.021 3.21 0.064
Concentration 2 0.1100 0.055 8.47 0.003
R X c 4 0.019 0.005 0.72 0.587
Error 18 0.117 0.007
Total 26 0.289
230
Table 012. Curve Area, psi (CA) El Paso Field Mix 39.2F.
Rubber
A B c
58.6 56.4 102.0 N 77.4 41.4 76.6 N 74.6 111.0 114.0
~
.. 71.8 80.4 86.2 s::
0 63.8 87.2 69.6 .,.. ood" +..) N 84.0 140.5 66.2
I ta ~
+..)
s:: aJ u s:: 0 35.0 71.0 58.8 u
70.6 73.2 110.0 ~ 52.6 76.0 83.8 N
Source df ss MS F Pr > F
Rubber 2 2017.4 1008.7 2.22 0.14 Concentration 2 831.5 415.8 0.92 0.42
R X C 4 2696.3 674.1 1.49 0.25
Error 18 8161.4 453.4
Total 26 13706.7
231
Table 013. Asphalt Modulus, psi (AM) El Paso Field Mix 39.2F.
Rubber
A B c
193.7 143.6 233.1 N 170.0 196.6 211.3 N 169.5 259.8 330.1
~
.. 250.6 228.4 241.6 s:::: 0 175.6 ?47.0 188.8 ·~ c::t +-J N 294.4 370.9 201.0 tO s..
+-J s:::: QJ u s:::: 0 87.5 189.0 157.7 u
218.4 171.6 194.5 1..0 161.4 163.8 250.2 N
Source df ss MS F Pr > F
Rubber 2 4741.4 2371.2 0.76 0.48
Concentration 2 20826.3 10413.1 3.32 0.06
R X C 4 21730.5 5433.1 1.73 0.19
Error 18 56479.7 3137.8
Total 26 103777.9
232
Table 014. Asphalt-Rubber Modulus, psi (ARM) El Paso Field Mix 39.2F.
Rubber
A B c
30.7 36.2 34.3 N 56.0 43.2 55.8 N 45.1 95.8 98.6
~ .. 61.2 82.4 60.7 s:::: 0 36.3 68.1 34.8 •r- ~
.f-) N 57.3 142.2 38.8
I ta s..
.f-)
s:::: Q) u s:::: 0 16.7 63.4 69.4 u
54.6 63.1 120.1 ~ 35.1 79.0 79.0 N
Source df ss MS F Pr > F
Rubber 2 4627.4 2314.2 3.87 0.04
Concentration 2 541.2 271.1 0.45 0.64
R X C 4 5382.1 1346.3 2.25 0.10
Error 18 10762.0 598.0
Total 26 21313.7
233
Table 015. Maximum Engineerinq Stress (MES), psi Buffalo Field Mix.
.s:.: C'l .,.. :I:
Source I Replication I I
lconcentrat ion j
I
I Digestion I
R X C R X D
c X D R X c X D
Error
Total
18
14.1 11.3 6.2
7.5 7.4 6.0
df
1
1
1
1
1
1 1
16
23
1
ss 5.29
152.89
292.57
3.15 3.84
63.68 5.30
431.00
957.72
234
22
27.2 27.5 6.9
12.6 7.9 5.2
MS
5.29
152.89
292.57
3.15 3.84
63.68 5.30
26.94
18
9.6 11.6 10.3
8.9 8.3 2.5
2
F
0.20
5.68
0.12
10.86 0.14
2.36 0.20
22
19.8 20.4 11.2
9.7 10.4 5.6
Pr > F 0.66
0.03
0.73
0.005 0.71
0.14 0.66
Table 016. Maximum True Stress (MTS), psi Buffalo Field Mix.
3 0 _J
Source i Replication !_
lconcentrat ion L I
I Digestion I
R X C R x D
C X 0
I R X c X D
Error
Total
18
72.9 54.1 29.8
4~.8 42.0 30.9
df
1
1
1
1
1
1
1
16
1
ss 115.9
1514.6
2572.2
218.2
2nn 4
234.6 142.8
6322.3
23 11387.0
235
22
85.4 71.9 33~2
71.3 44.4 28.5
MS
115.9
1514.6
2572.2
218.2
2FtFt a.
234.6 142.8
395.1
2
18 22
48.0 102.8 57.9 96.4 51.3 57.1
50.5 47.7 10.2
F
0.29
3.83
0.55
6.51
fl_6_7_
0.59 0.36
55.0 58.3 27.5
Pr > F
0.59
0.06
0.46
OQZ
_o_ Ll. 'l
0.45 0.55
Table 017. Maximum Engineering Strain (MES) in/in Buffalo Field Mix.
Source
I Replication ;
!concentration i !
I Digestion I i
I R X C I R X D
C X D I R X c X D i
Error
Total
3 0
.....J
..c C'l .,..
18
5.75 5.44 5.64
7.03 7.28 7.50
df
1
1
1
1 1
1 1
16
23
1
ss 0.627
3.496
12.514
2 RR4
1.515
0.549. 0.001
6.854
21.57 R
236
22
2.95 2.95 5.69
5.80 6.40 6.10
MS
0.627
3.496
12.514
2 RRLL
1.515
0.549
0.001
0.428
18
5.72 6.05 5.50
6.83 6.19 6.13
2
F
1.46
8.16
29.21
h 7<
3.54
1 ?R
0.00
22
5.38 5.05 5.68
5.90 7.16 6.83
Pr > F
0.24
0.01
0.0001
n n1
0.07
0 27
0.95
!
I I
Table 018. Maximum True Strain (TSF), in/in Buffalo Field Mix.
Source Replication
Concentration
D1gestion
R X C R X D
c X D
R X c X D
Error
Total
18
1.91 1.86 1.89
2.09 2.11 2.14
df 1
1
1
1
1
1
1
16
23
1
ss 0.0254
0.1001
0.3128
n n.R?.R
0.0523
0.0301 0.0035
0.2223
0.8292
237
22
1.37 1.37 1.90
1.93 2.00 1.96
MS
0.0254
0.1001
0.3128
n n.R?.R
0.0523
(). 0301
0.0035
0.0139
18
1.91 1.95 1.86
2.05 1.97 1.96
2
F
1.82
7.21
22.52
t:; Oh
3.76
2:17
0.25
22
1.85 1.80 1.89
1.93 2.10 2.05
Pr > F
0.19
0.01
0.0002
n n?
0.07
n 1n
0.62
Table 019. Curve Area (CA), PSI -- Buffalo Field Mix.
~· 0 _J
Source I Replication I I
lconcentrat ion i I j Digestion I I I
R X C . R x D
C X 0 R X C X 0
Error
Total
18
72.5 52.2 29.8
44.4 42.9 36.6
df
1
1
1
1 1
1 1
16
23
1
ss 102.1
689.0
1902.6
266.6 320.4
94.4 80.7
4681.3
8137.1
238
22
69.9 65.8 31.9
63.9 45.4 25.9
MS 102.1
689.0
1902.6
266.6 320.4
94.4 80.7
292.6
18
48.1 59.6
' 50.1
54.1 41.1 10.1
2
F ·0.35
2.35 '
6.50
0.91 1.10
0.32 0.28
22
91.9 84.3 56.7
52.5" 52.7 29.4
Pr > F 0.56
0.14
0.02
0.35 0.31
0.57 0.60
Table 020. Asphalt Modulus, (AM), psi Buffalo Field Mix.
Source : Replication ! Concentration
I
I Digestion I
I
R X C
R X 0
C X 0
R X c X D
Error
Total
3 '0 -I
..c: C'l
•r-:::c
18
81.9 94.6 43.1
66.8 38.9 47.0
df
1
1
1
1
1
1 1
16
23
1
ss 470.2
9104.0
23087.3
786.3
1426.6
5965.3 3348.3
38716.8
82904.7
239
22
209.7 286.2 40.4
52.1 54.6 31.T
MS
470.2
9104.1
23087.3
786.3
1426.6
5965.3
3348.3
2419.8
18
105.3 67.1 79.5
66.0 51.2 18.7
2
F 0.19
3.76
9.54
0.32
0.59
2.47 1.38
22
132.4 145.4 80.5
77.8 71.9 45.0
Pr > F 0.66
0.07
0.01
0.57
0.45
0.13 0.25
Table 021. Asphalt-Rubber Modulus, (ARM), psi Buffalo Field Mix.
Source I Replication i I
! . !Concentration L
I Digestion I
I R X C
R X D
C X 0
i R X C X 0
Error
Total
18
58.0 43.3 26.2
30.0 30.1 22.3
df
1
1
1
1
1
1 1
16
23
1
ss 106.4
1292.4
1865.9
?R4 7
335.5
111.6 503.1
3915.6
8415.2
240
22
64.4 39.5 32.4
61.0 32.8 26.6
MS
106.4
1292.4
1865.9
?Rd 7
335.5
111.6
503.1
244.7
18
34.5 41.9 38.1
39.2 32.6 7.76
2
F
0.43
5.28
7.62
1 1fi
1.37
0 46
2.06
22
91.4 83.7 44.5
46.3 35.3 22.2
Pr > F
0.51
0.03
0.01
n ?Q
0.25
0 50 0.17
Table 022. Maximum Engineering Stress (MES), PSI --Buffalo Lab Mix.
Concentration, %
18 22
17.3 19.6 ~ 19.6 21.6 0
..J 21.2 18.0
c: 13.4 11.3 0 .,... 16.0 10.8 ...., -c 111 0 15.7 9.2 QJ ~ 0') .,.... Cl
5.59 5.21 .s:::. 5.02 7.71 0') .,... 6.99 8.56 :I:
Source df ss MS F Pr > F
Digestion 2 508.0 254.0 111.9 0.0001
Concentration 1 3.8 3.8 1. 7 0.22
D X C 2 28.4 14.2 6.3 0.01
Error 12 27.2 I 2. 3
Total 17 567. 4
241
Table 023. Maximum True Stress (MTS), PSI -- Buffalo Lab Mix
Concentration, %
18 22
50.2 80.0 3 58.2 73.5 0 63.4 66.9 _J
c 56.9 66.5 0 ...... 74.3 61.5 ...., " (/) 0 75.2 55.0 QJ ~
C') ...... 0
28.5 28.4 ..c 24.5 41.8 C') .,... 36.4 47.4 ::I:
Source df ss MS F Pr > F
Digestion 2 3758.3 1879.2 31.5 0.0001
Concentration 1 157.2 157.2 2·.6 0.13
D X C 2 458.9 229.5 3.8 0.05
Error 12 716.4 59. 7·
Total 17 5090.8
242
Table 024. Maximum Engineering Strain (MES), in/in Buffalo Lab Mix.
Concentration, %
18 22
4.77 4.48 3: 4.14 3.75 0 4.10 4.70 ...J
c 5.70 5.91 0 .,... 5.07 6.48 ....., ""C (/) 0 4.93 6.27 CIJ :E Cl .,...
0
6.23 6.75 .c 7.80 6.03 Cl .,... 5.58 6.40 :::z::
Source df ss MS F Pr > F
Digestion 2 14.24 7.12 20.50 0.0001 Concentration 1 0.35 0.35 0.97 0.34
0 X C 2 1. 22 0.61 1.67 0.22 Error 12 4.24 0. 35
Total 17 20.05
243
Table 025. Maximum True Strain (TSF), in./in. Buffalo Lab Mix.
Concentration, %
18 22
1.75 1.70 3: 1.63 1. 56 0 1.63 1.73 ...J
t: 1.89 1. 9·2 0 .,... 1.80 2.01 +o) -c VI 0 1.78 1.98 Q) :::E 01 .. ,...
0
1.98 2.04 ..c: 2.17 1.96 01 .,... 1.89 2.00 :I:
I
Source df ss MS F Pr > F
Digestion 2 0.360 0.180 25.9 0.0001
Concentration 1 0.008 0.008 1.16 0.30
D X C 2 0.024 0.012 1.72 0.22
Error 12 0.083 0.007
Total 17 0.475
244
Table 026. Curve Area (CA), PSI Buffalo Lab Mix.
Concentration, %
18 22
60.1 77.3 ~ 67.8 69.0 0 68.7 69.7 _,J
!: 62.2 58.7 0 .,.... 73.0 58.4 +-> "'C (/) 0 70.8 63.3 (l) :e: 0"1 .,....
0
29.7 30.9 ..c 80.5 40.4 0'> .,.... 34.2 46.0 :J:
Source df ss MS F Pr > F
Digestion 2 3691.6 . 1845.8 75.7 0.0001
Concentration 1 7.6 3.8 0.3 0.58 I
0 X C 2 392.2 196.1 8.0 0.01 l Error 12 292.8 24.4
Total 17 4384.2
245
Table 027. Asphalt Modulus (AM), PSI Buffalo Lab Mix.
Concentration, %
18 22
130.7 123.6 3: 138.7 129.2 0 -I 133.9 94.6
c 121.9 76.6 0 .,... 118.3 61.2 ......, -c C/) 0 84.5 64.6 QJ :::E: ~ .,... Cl
45.8 34.1 ..c:: 36.1 49.7 ~ .,... 36.1 47.1 ::c
Source df ss MS F Pr > F
Digestion 2 21036.0 10518.0 66.30 0.0001
Concentration 1 1514.9 1514.9 9.55 0.01
0 X C 2 1521.8 760.9 4.80 0.02
Error 12 1903.6 158.6
Total 17 25976.3
246
Table 028. Asphalt-Rubber Modulus (ARM), PSI. Buffalo Lab Mix.
Concentration, %
18 22
20.4 55.4 3 28.5 46.2 0 31.2 43.2 ....J
c: 39.0 55.7 0 ·~ 57.1 54.4 of-) "'0 (/) 0 59.3 47.4 QJ ~ 0'1 •.-c
22.5 22.6 ..c 16.7 35.8 0'1 .,_ 30.7 43.7 ::t:
Source df ss MS F Pr > F
Digestion 2 1691.7 845.9 13.4 0.001
Concentration 1 545.5 545.5 8.7 0.01
D X c 2 325.7 162.9 2.6 0.11
Error 12 755.3 62.9
Total 17 331$.3
247
N ,.J:::--00
Table 029. Softening Point, F, El Paso Lab Mix.
~ A 0
0
22 24 26 22 "
116.9 122.6 123.8 118.5 ~ 117.0 117.5 123.1 117.8 0 _J 116.5 116.0 122.9 114.1
124.3 121.9 112.3 124.3 " 113.4 108.9 110.1 116.4 0 :E 110.4 116.9 118.0 119.0
111.6 116.3 116.5 123.5 .s:: 116.3 111.9 116.6 114.1 0'1 ·r- 116.8 117.5 113.4 119.3 :X:
B c
24 26 22 24 26
123.4 123.5 118.0 120.6 117.8 119.8 118.3 121.3 114.3 112.8 112.5 120.1 118.3 115.5 116.4
123.5 113.6 123.9 126.5 120.4 112.4 116.6 122.9 118.1 125.9 116.0 115.0 116.1 114.4 109.5
116.8 118.8 124.8 129.4 115.5 124.1 112.5 111.6 118.9 120.0 116.3 119.1 121.5 116.1 119.5
N ..t:-\0
Table 029, (continued). Softening Point, El Paso Lab Mix.
Source df ss MS Rubber 2 70.40 35.20
Concentration 2 6.91 3.50 Digestion 2 15.42 7.71
R X C 4 34.33 8.61
R X D 4 144.45 36.11 c X D 4 78.99 19.72
R X c X D 8 65.90 8.20
Error 54 1084.41 20.10
Total 80 1500.91 - - - ----- -----
I
F Pr > F I
1.74 0.18 _l
0.17 0.84
' I
0.38 0.68 I I
I 0.43 0.79 I
I
I
I 1.80 0.14 !
0.98 0.42
0.41 0.91
Table 030. Softening Point, F (SP), El Paso Field Mix.
Rubber
A B c
113.1 113.3 118.0 C\J 110.3 115.2 116.1 C\J
117.6 115.1 120.5
~
.. c 118.4 116.1 111.0 0 .,..... oo:::t 114.3 116.0 112.0 +.l N n3 119.2 120.6 116.0 s.. +.l c (]) u I: 0 u 118.0 113.0 120.0
\.0 117.1 114.5 120.0 C\J 118.0' 119.5 118.0
Source df ss MS F Pr > F
Rubber 2 10.31 5.16 0.58 0.57 Concentration 2 39.53 19.76 2.21 0.14
R X C 4 97.30 24.33 . 2. 71 0.06
Error 18 161.28 8.96
Total 26 308.43
250
Table 031. Softening Point, F, Buffalo Field Mix.
..c:: C') .,...
:r:
r Source
I Replication (e) i
!concentration i
(c) I
! Digestion (d) I
R X c R X D
C X 0
I R X C X 0
. Error
Total
18
116.6 116.0 118.0
111.0 110.4 109.8
df
1
1
1
1
1
1
1
16
23
1
22
116.5 117.3 119.3
117.9 118.0 121.4
ss 13.88
147.51
107.32
0.21 17.51
1.90
70.04
59.53
417.90
251
MS
13.08
147.51
107.32
0.21
17.51
1.90 70.04
3.72
18
114.9 116.4 118.3
111.5 116.8 112.0
2
F
3.73
39.65
28.84
0.06
4.71
0.51
18.82
22
126.0 126.5 121.0
114.8 117.1 115.3
Pr > F
0.07
0.0001
0.0001
0.81 0.05
0.49 0.001
Table 032. Softening Point, F, Buffalo Lab Mix~
Concentration, %
18 22
115.3 124.0 ~ 116.8 124.4 0
.-J 114.8 123.0
c 0 116.6 118.3 •r-~ ~ 123.4 118.4 (/) 0 Q) ~ 120.1 118.1 en
•r-Cl
.c 103.3 108.6 en 101.1 116.8 .,.. :I:
I 112.4 112.1
Source df ss MS F Pr > F
Digestion 2 432.22 216.11 19.65 0.0001
Concentration 1 88.45 88.45 8.04 0.02
0 X C 2 87.69 43.85 3.99 0.05
Error 12 132.02 11.00
Total 17 740.38
252
APPENDIX F.
Specification for Asphalt-Rubber Seal Coats and Interlayers
253
1. DESCRIPI'ION -----·--This work involves placement of an asphalt-rubber treatment on a
prepared pavement surface in accordance with the plans and other
specifications.
This specification describes two known proprietary processes for
production of the treatment hereinafter known as Method A ann Methorl B.
Method A uses ground vulcanizeii rubber and an extender oil, whereas
Method 'B uses qround vulcanized rubber and a kerosene ctiluent. Either
method is acceptable basect on proper canpliance with the specification
and certification of material.
2. . MATERIALS ----~--·-···-
2.01 ASPHALT.C~~JJ Asphalt cement shall meet the requirements of
AASHTO M 20-70 (Table 1.), ~226-80 (Table 1), or M226-80 (Table 3).
Acceptable qrades for the respective materials will depend on
location and circumstances and may require approval of the supplier
of the Asphalt-Rubber. In addition, it shall be fully compatible
with the ground rubber proposed for the work as determined by the
supplier.
2.0~ .?J-!~BE~. £:?(fENDER.S1J:L t~Jff!JJ~OD ~1: Extender oil shall be a resinous,
hiqh flash point aromatic hydrocarbon meeting the followinq test
requirements:
Viscosity, SSU, at 100 F (ASTM D 88)
Plash J?oint, COC, degrees F (AS'IM D 92)
Molecular Analysis (AS'IM D 2007):
Asphalteness, Wt. percent
Aromatics, Wt. percent
254
2500 min.
390 min.
0.1 max.
55.0 min.
l:.9.l.K.~§Et!~-TII!~ • ..!1ILQENT ~~~E'11f9.P B), 'Ihe kerosene-type diluent used shall be compatible with all materials used and shall have a flash point
(AS'IM D92) of not less than ROF. 'Ihe initial boilinq point shall not be
less than 300 F with total oistillation (dry point) before 450 F (AS'IMD
850). The Contractor is cautioned that a normal kerosene or range oil
cut may not be sui table.
2.04 G~UND RUBBER q.>J1~t@:!TS•
A. ~~ MEfBOq A1 The rubber shall meet the following physical and
chemical requirements.
Two types of ground rubber shall be blended. Rubber Types 1 and 2
shall meet the following 'test requirements as described by AS!M 0297:
'Ihe rubber shall be blended such that the resultirg material conforms
to test requirements as indicated below:
Specific Gravity 1.15 1 . 17 1 .12 1.14 1.14 1 .16
Total Extract, w percent 14 21 8 12 12 15
Ash, w percent 3.0 6.3 3.8 4.2 4.5 5.5
Free Carbon, w percent 28 32 27 29 27.5 29.5
Total Sulfur, w percent 1 .0 1 .2 1 .0 1.2 1 .0 1 .2
Rubber Polymer: Natural Rubber, w percent 18 32 85 95 50 60
Styrene Butadiene, w percent 58 82 5 15 35 45
Polybutadiene, w percent 0 12 0 0 4 8
Rubber Hydrocarbon, w percent 50 65 50 60 55 65
255
'!he rubber blend shall be dry and free flowing, free of wire, fabric,
or other contaminants except up to 4 Wt. percent of mineral powder
may be included to prevent sticking of particles. Rubber
constituents and moisture content shall be such that when mixed with
asphalt, foaming of the resultinq blend does not occur.
SIEVE ANALYSIS (~STM C-136)
Sieve Number .. rl .. • .........
Percent Passw
8 100
30 30-50
50 5-30
100 0-5
~ FOR ME~RP ry, The rubber shall be a ground tire rubber, 100 percent
vulcanized, recarmended by the Contractor for this use with the approval
of the Engineer, meeting the followinq requirements:
CCl'-1IDSITION. 'The rubber shall be qround tire rubber, dry and free
flowing, free from fabric, wire, or other contaminating materials
except that up to 4 Wt. percent of calcium carbonate shall be
included to prevent sticking together of the particles. Properties
of the rubber shall conform to requirements shown below for tests
described by ASTM D297.
Specific Gravity
Tbtal Extract, w percent
Ash, w percent
Free Carbon, w percent
Total Sulfur, w percent
Rubber Pol yrner:
Natural Rubber, w percent
Styrene Butadieve, w percent
256
Min -1.15
1
3
28
1.0
18
58
Max -1.17
21
6.3
32
1.2
32
82
'R)l ybutadiene, w percent
Rubber Hydrocarbon, w percent
0
50
12
65
Rubber constituents and moisture content shall be such that
when mixed with asphalt, foaming of the resulting blend
does not occur.
SIEVE ANALYSIS (&STM C-136).
Sieve Number , .... , ..... 8
10
30
50
PerqE(nt ?ass;l.ng
100
98-100
0-10
0-2
2~05 ,A\,CRffiATF§..: Cover aggregates shall be a dry, clean material meeting
the requirements of MSH'IO M 283-81 and the additional requirements
listed below:
A. Only crushed stone or slag will be acceptable (hot or precoated
aggregates, if used, will be by special provisions in the documents).
B. The aqgreqate shall not contain more than 5 wt. percent chart or
other known stripping material.
c. Gradation shall be according to ~STM C 448-80, Size 7 with the
addition that no more than 1 Wt. percent shall pass the Number 50
sieve.
D. The aggregate shall be essentially free of deleterious material
such as thin, elongated pieces, dirt, dust, and shall contain not
more than 1 Wt. percent water when tested in accordance with AS'IM C
566.
2.06 TACK COAT (~~.'!HQD~ .. A, ~~· 'Ihe tack coat shall be as shown on the
plans or as directed by the Engineer.
257
2,.0711
REB.;J;'IF;I;<:;~'!'JQN f\NDdQU~lj!'IY ~SS,qRANCE, Prior to application, the
Contractor shall submit certification of specification compliance for all
materials to be used in the work. Also certification shall be sutmitted
concerning the design of the asphalt-rubber blend as follows:
A. METHOD A. The Contractor shall submit certification
that the asphalt cement is compatible with the rubber and
has been tested to determine the quantity of extender oil
(usually 1 to 7 Wt. percent) required and that the proposed
percentage will produce an absolute viscosity of the blenden
materials of 600 to 2000 poises at 140F when tested in
accordance with the requirements of .MSH'IO T 202-80. New
certifications will be required if the asphalt cement grade
or source is changed.
B. METHOD B. The Contractor shall submit certifications
that the asphalt cement is compatible with the rubber. New
certifications will be required if the asphalt cement qrade
is changed.
c. FOR EI'IHER ME'IHOD. The Contractor shall subnit
information (that will vary with the location) that shows,
to the satisfaction of the Enqineer, that the asphalt-ruhber
and aggregate canbination proposed for the proiect will not
be subiect to water stripping in the environmental exposure
of the project.
3,. f2U!l;MJ!LT
3,. 01 PREBLENDI.NC]; Rubber and a -portion of the asphalt for the
asphalt-rubber blend shall be preblenderl in a master batch prior
to int~uction of the master batch to the distributor. The
master batch can be diluted with additional asphalt and
additives in the distributor to the formulation recommended by
the Supplier.
258
3.02 DISTRIB~ At least one pressure-type bituminous
distributor in gcx:x1 condition will be required. The distributor
shall be equipped so as to be capable of even heating of the
material up to 425F, have adequate pump capacity to maintain a
high rate of circulation in the tank~ have adequate pressure
devices and suitable manifolds to provide constant positive
cutoff to prevent dripping from the nozzles. The distributor
bar shall be fully circulating with nipples and valves so·
constructed that_ they are in such intnnate contact with the
circulating asphalt that the nipples will not became partially
plugged with congealing asphalt upon standing, thereby causing
streaked or irregular distribution of the asphalt. Any
distributor that produces a streaked or irregular distribution
of the material shall be promptly rerroved from the proiect.
Distributor equipn.ent shall include a tachaneter, pressure
gages, volume measuring devices, and a thermometer for reading
temperature of tank contents. The asphalt-rubber sections shall
be so constructed that unifonn applications may be made at the
specified rate per square yard within a tolerance of plus or
minus 0.03 gallons per square yard. It is suggested that the
distributors used for Method B be equipped with mechanical
mixing devices.
3,03 CHIP s~~~ A self propelled chip spreader in good
condition and of sufficient capacity to apply the aggregate
within the time period specified is required. The spreader
shall be so constructed that it can be accurately gauqed and set
to unifonnily distribute the required amount of aggregate at
regulated speed.
259
~e04 ~RQ9MS 1 Revolving brooms shall be so constructed as.to
sweep clean or redistribute aggregate without damage to the
surface.
3.05 PNEUMATIC TIRE ROLLERS. 'll1ere shall be at least three -----~--~._~~~~~~~~
multiple-wheel pneumatic-tired self-propelled rollers with
provisions for loading to at least eight tons and at a tire
inflation pressure as required by the Engineer with a minimum
3,000 pounds per wheel.
3 r06 TRUCKS, Trucks of sufficient number and size to adequately
supply the material will be required and shall be properly
equipped for use with the chip spreader.
3.07 MUNICIPAL TYPE STREET SWEEPER. If the Contractor intends
to put traffic on the asphalt-rubber surface treabment or
interlayer, it may be necessary to sweep the surface with a
Municipal Type Street Sweeper in urhan areas and revolving broom
in rural areas to pick up and/or remove stone and dust lodged in
. the surface.
A. PREPARATION OF ASRIALT-.EXTENDER OIL MIX BLEND. Blend
the preheated asphalt cement (250 to 400F), and sufficient
rubber extender oil (1 to 7 Wt. percent) to reduce the
viscosity of the asphalt cement-extender oil blend to within
the specified viscosity range. Mixing shall be thorough by
recirculation, mechanical stirrinq, air agitation, or other
appropriate means. A. minimum of 400 gallons of the asphalt
260
cement-extender oil blend shall be prepared before
introduction of the rubber.
B. PREPARATION OF ASmALT-RUBBER BINDER. 'Ihe
asphalt-extender oil blend shall be heated to within the
range of 350 to 425F. '!he asphalt-rubber hlend for the
master batch shall preblended in appropriate preblending
equipment as specified by the supplier prior to introduction
of the master batch into the distributor. Addition of
·asphalt cement into the distributor to provide the specified
formula shall be as directed by the supplier. The
percentage of rubber shall be 20 to 24 Wt. percent of the
total blend as specified by the supplier. Recirculation
shall continue for a min~ of 30 minutes after all the
rubber is incorporated to insure proper mixing and
dispersion. Sufficient heat should be applied to maintain
the temperature of the blend between 375 and 425F while
mixing. Viscosity of the asphalt-rubber shall be less than
4,000 centipoises at the tnne of application (ASTM D 2994
with the use of a Haake type viscometer in lieu of a
Brookfield Model LVF or LVT if desired).
4.02. ~P~1'ION 0~ BINQE~.f.OR 1 ME'IHQD B:
A. PREPARATION OF 'IHE ASmALT-RUBBER BLF.ND-MIXIJ.\Ki.
The asphalt cement shall be preheated to within the range of
350 to 450F. The asphalt-rubber blend for the master batch
shall be preblended in appropriate preblending equipnent as
specified by the supplier prior to introduction of the
master batch into the distributor. Addition of asphalt
cement and diluent into the distributor to provide the
specified formula shall be as directed by the supplier. The
percentage of rubber shall be 20 to 24 wt. percent of the
total asphalt-rubber mixture (including diluent). Mixing
and recirculation shall continue until the consistency of
261
the mixture approaches that of a semi-fluid material (i.e.,
reaction is complete). At the lower temperature, it will
require approxnnately 30 minutes for the reaction to take
place after the start of the addition of rubber. At the·
higher temperature, the reaction will take place within
approximately five minutes; therefore, the temperature used
will depend on the type of application and the methods used
by the Contractor. Viscosity of the asphalt-rubber shall be
less than 4,000 centipoises at the time of application
( AS'IMD 2994 with the use of a Haake type viscometer in 1 ieu
of a Brookfield Model LVF or LVT if desired). After
reaching the proper consistency, application shall proceed
irnnediately.
B. ADJUSTMENT 'ID SPRAYING VISCOSI'IY WI1H DILUENT. After
the full reaction described in MIXING (4.02) above has
occurred, the mix can be diluted with a kerosene type
diluent. The amount of diluent used shall be less than 7.5
percent by volum.e of the hot asphalt-rubber canposit.ion as
required for adjusting viscosity for sprayinq or better
we~ting of the cover aggregate. Temperature of the hot
canposition shall not exceed the kerosene initial boilinq
point at the tUne of adding the diluent.
4.03.JOB DELAYS. Prior to preparation or use of asphalt-rubber
(prepared by either Method A or B), maxirm.nn holdover times due
to job delays (time of application after canpletion of reaction)
to be allowed will be agreed upon between the Contractor,
Supplier, and F:ngineer. However, holdover tUnes in excess of 16
hours will not be allowed at temperatures above 290F.
Retemperi.nq by additional heating and/or addition of asphalt
rubber, or diluent (kerosene/extender oil) will be allowed with
approval of the Engineer.
262
4.04 SEASQ~ ~ ~THEB LIMJlTATIONS1 Placement of the
asphalt-rubber surface treatment or interlayer shall be made
only under the following conditions:
A.. Ambient air temperature l.s above 60F ann r:i.si.nq.
B. The pavement surface for application is absolutely dry.
c. The wind conditions are such that a satisfactory
membrane application can be achieved.
4.ps PREPARATION $)F SURFACE, Prior to the hot asphalt-rubber
treabment, the entire surface to be treated shall be cleaned as
required by sweeping, blowing, and other methods until all d~st,
mud, clay lumps, and foreign material are rennved entirely from
the area. Patching may· be required. No moisture should be
present on the surface. After cleaning and patching, the
surface shall receive a tack coat if directed by the Engineer.
4.06 APPLIC~Ip~ OFJ f}INpER.- 'Ihe material shall be applied at a
temperature of 375 to 425F for Method A. and 290 to 350F for
Method B. 'Ihe rate shall be specified by the Engineer, but
should generally be 0.35 to O.fi5 gallons per square yard. No
shot shall be in excess of ·a length which can be nnmediately
covered with aggregate. The Contractor is reminded that the
traffic in the adjacent lane must be protected from
asphalt-rubber aggregate, and sweepings. Application width may
have to be adjusted to protect this traffic.
The application from the distributor shall be stopped when the
tank contains less than 300 gallons of blended asphalt-rubber.
At all startings, which shall include joints with preceeding
application, intersections, and at junctions with all pavements,
etc., a property ;unction shall be made to insure that the
distributor nozzles are operating at full force when the
263
application begins. Building paper or other suitable devices
shall be used to receive the initial application from the
nozzles before any material reaches the road surface at the
joint.
The paper or other suitable device shall be removed immediately
after use without spilling surplus material on the road surface.
During the application of binder, the Contractor shall provide
adequate protection to prevent marrinq or discoloration of
pavement, structures, curbs, trees, etc., adjacent to the area
being treated.
Longitudinal ioints shall be reasonably true to line and
parallel to the centerline. 'Ihe overlap in the application of
the binder shall he the min~um to assure complete coverage.
Where any construction ioint occurs, the treatment of the edqes
shall be blended so there are no gaps and the elevations are the
same and free from ridges and depressions.
When the application of binder is on less than the full width of
treatment, the aqgreqate shall be spread only to within eight
inches of the edge of the next application until the binder is
applied to the adjacent width.
Between shots no substantial quantity of binder shall remain in
the spray bars or nozzles.
4.07 APPLICATION OF COVF.R AC.:l;:ROC-ATP.. 'Ihe application of _.. ___ ..__...._ ____ ...... ___ ........... ..... ...... . -
aggregate shall follow immediately after the application of
binder. The hot application of binder shall not be made further
in advance of the spreadinq of the cover aggregate than can be
covered imnediately. 'Ihe distributor and the agqreqate spreader
shall not be separated by more than 150 feet.
264
Spreading of the aggregate shall be done directly fran approved
spreaders. Trucks and spreaders shall not drive on the
uncovered binder.
The dry aggregate shall be spread uniformly to cover the binder
with an amount of mineral aggregate such that no more than one
layer of mineral aggreqate is applied, this quantity is
generally 25 to 40 pounds per square yard but will be as
directed by the Engineer. Any deficient areas shall be covered
by additional material.
'Ihe entire application of cover material shall be rolled as soon
as possible after application. 1Rolling shall continue to be (
repeated as often as necessary to key the cover material
thoroughly into the binder over the entire surfac.e.
Pneumatic tire rollers shall be used in the sequence and
canbination which will provide the rolling pattern that results
in the best adhesion of the aggregate to the binder and the best
surface qualities.
Any loose cover aggregate not embedded after initial rolling·
shall be removed by sweepinq. Deficient areas where loose
aggregate has been removed may have blotter sand applied to
prevent traffic from removing embedded coarse aggregates.
All such rolling shall be performed while the temperature is
favorable for seating the aggregate into the binder.
In no case shall there be less than three complete coverages
with pnetnnatic tire rollers of the entire surface of the
treatment after initial placement. A.ddi.tional coverage, may be
necessary if directed by the Engineer.
When the Engineer has determined that the maxnnum amount of
cover aggregate has been embedded, the Contractor shall sweep or
otherwise remove all loose material from the entire surface at
such time and in such manner as will not displace any embedded
aggregate.
265
'Ihe completed asphalt-rubber surface treatment or i.nterlayer
shall be allowed to cure for a minnnum period as directly by the
Engineer prior to placing any final overlays. Traffic will not
be permitted on the asphalt-rubber surface treatment or
interlayer until it has cured and the embedded cover aggregates
are tightly bound to the surface such that they will not be
dislodged by traffic.
'!be Engineer may require the surface to be swept with a
municipal type street sweel;)er should power broominq fail to
remove all stone and dust particles from the surface which would
in his opinion be detrimental to traffic.
~MElliQQ 0~ MEAStJREMEN'J;'1
The asphalt-rubber surface treatment or interlayer will be
measured by the number of square yards of compacted material in
place.
6. BASIS OF PAYME~T1
'Ihe unit price bid per square yard shall include the cost of
furnishing all material, all labor and equipment necessary to
complete the work. Payment for patching material and tack coat
will be made under the appropriate items.
7 • ALTERNATE M.E'lliOD OF .MEASUREMENT AND BASIS OF PAYMENT.
An alternate method of measurement and basis of payment is based
on actual quantities used for the asphalt-rubber application.
Asphalt-rubber (including diluent and/or extender oil) and cover
aggregate will be measured by the ton of materials actually used
for the project. All materials will be weighed in the vehicle
at the time and place of unloading or at such other points as
may be directed by the Engineer.
266
'lhe amount of cc:;Jrpleted and accepted work, measured as provided
above, will be paid for at the contract price per ton for
"Asphalt-Ruhber" and at the contract price for "Cover
Aqgregate".
267